FIRST, most who, at least, give mental agreement to this one ground will agree that we must preach this to the lost. What is the great problem of the religions of man. They motivate sinners, in some way or some form, to trying to establish a righteousness of their own. By nature, sinners know nothing of grace, of a righteousness imputed as the only ground of salvation. By nature, all we know is "do and live; disobey and die." The Gospel must be preached out so as to distinguish the true and living God from an idol, the true Christ from a counterfeit, so that sinners might not remain deceived. The Gospel must define the only ground of salvation, the imputed righteousness of Christ, so as to exclude anything and everything that sinners plead by nature in seeking to remove God's wrath and gain God's favor. As long as any sinner continues to seek after and expect salvation or any part of it based on anything other than the imputed righteousness of Christ, they will remain lost.
 

The goal of the Gospel as towards the lost sinner is to call them to faith towards God and repentance from dead works. God will save no sinner apart from faith. But faith is opposed to works as it believes and rests in a righteousness imputed. Faith expects God to save us and glorify us based upon the righteousness of Christ, with no consideration of or contribution from our efforts at obedience. (1) FAITH BELIEVES GOD'S PROMISE OF SALVATION CONDITIONED ON CHRIST ALONE, BECAUSE FAITH KNOWS THE GOD WHO MADE THE PROMISE. (2) FAITH RECEIVES THE IMPUTED RIGHTEOUSNESS OF CHRIST AS THE ONLY GROUND OF SALVATION, BECAUSE IT KNOWS AND LOVES CHRIST WHO ESTABLISHED THIS GROUND.
 

Receiving Christ by faith always produces Godly repentance, repentance unto life or repentance that evidences spiritual and eternal life. Before justifying faith all repentance is legal, natural conscience sorrow, called the sorrow of the world which works death. This legal repentance always leads sinners to trying to establish their own righteousness for relief. The Gospel removes the cloak of self-righteousness and exposes all efforts at worship and morality before justifying faith as fruit unto death. Preaching this Gospel, then, is necessary to bring sinners to saving faith and true repentance, to salvation.
 

SECOND, we must constantly preach it to the saved. This is what the Apostle Peter told his hearers in 2 Peter 1:12-15. His desire, His last wishes, was that they be a people who are marked and identified by this great message of God's free and sovereign grace in Christ. Peter wanted them to be established with this truth. So he told them that it was not a burden to him to remind them continually of this and to motivate them to diligent obedience, perseverance, and courage in the faith of Christ with this truth. Why is it necessary for Gospel preachers to preach this specific truth continually to those who are saved.
 

I. IT IS NECESSARY TO DISTINGUISH GOD'S PEOPLE AND THEIR WORKS FROM THE WORLD AND ITS WORKS (Matthew 5:13-16).
 

The command of Christ in Matthew 5 and in the Great Commission is for His disciples to spread this great message of salvation conditioned on Him alone and based on His righteousness alone throughout the world. It is by this message that God's people are distinguished and identified as being separate from the world. If we lose that distinction, then we are no more than salt that has lost its savor. This would reveal that we were never saved at all. The "light" in Matthew 5:16 is not the works of believers. IT IS THE GOSPEL OF ETERNAL SALVATION AND FINAL GLORY BASED ON THE RIGHTEOUSNESS OF CHRIST FREELY IMPUTED AND RECEIVED BY FAITH. This light shines on the works of believers and reveals these works to be "good works" (John 3:21; Eph. 2:10).
 

The Gospel reveals the obedience of believers to be good works, not because these works measure up to the standard of God's holy law. Our works after salvation still fall short of the law's requirement. That is why we must continually cry, "O wretched man that I am" (Rom. 7:24). This is why a true believer constantly sees his need of Christ, His blood and righteousness. We must continually confess the sinfulness of our best efforts as to the ground of salvation and our continual need of cleansing and forgiveness in Christ (Phil. 3:9). The Gospel reveals that the works of believers are good not because they sanctify us or make us holier. Our works after salvation are not good enough to do this. We who believe the Gospel must see ourselves as already complete in Christ (Col. 2:9-10) -- completely pardoned and forgiven of all sin; completely fit and qualified for the presence and fellowship of God; and completely entitled to the whole inheritance of grace, all based on the righteousness of Christ.
 

The Gospel reveals the obedience of believers to be good works as they are: (1) performed by one who is in a justified state (justified by the grace of God in Christ), (2) the fruit of justifying faith (not seeking salvation or any part of it based on such works, but in light of having obtained all of salvation in Christ), and (3) the product of God's grace in our lives and evidences of His power and goodness (John 3:21). In other words, the works of believers are acceptable to God as they are motivated, not legally, but by grace and thanksgiving as summed up in the absolute certainty of eternal salvation and final glory based on the righteousness of Christ. Believers are to be obedient, dedicated people, going about seeking to do good. But as we go about seeking to do good, we must let our light shine so as to testify to the world that we expect no salvation or blessing from God based on our good works. We expect salvation and eternal life from God based on the obedience and death of Christ our Lord and Savior. If sinners see and believe this by the power of God, then they will glorify God and not men.
 

This same light exposes the works and efforts of unbelievers to be "fruit unto death," "evil deeds," and "dead works" (Rom. 7:4, John 3:19-20; Heb. 9:14). Until this specific light shines in the preaching of the doctrines of Christ, the doctrines of grace, the Gospel, men and women by nature do not know that such deeds are evil. They are deceived by sin (Jer. 17:9; Rom. 7:11). The Gospel reveals in the light of Christ and Him crucified, His blood, and His righteousness as the only ground upon which God can justify the ungodly, that all of man's efforts to establish a righteousness of His own is nothing but "dung" (Phil. 3:7-10) and can only leave a sinner in a state of condemnation (Rom. 10:1-3). The Gospel reveals the works of unbelievers to be evil, not because these works are necessarily immoral and insincere. It reveals them to be evil as they are: (1) performed by one who is a condemned, guilty state (and in that state a sinner's person and works are accursed), (2) done in unbelief (and without faith it is impossible to please God), and (3) the fruit and effect of self-righteousness. In other words, apart from a saving knowledge of the righteousness of Christ as the only ground of salvation, our motive can only be legal, thinking that salvation or some part of it is conditioned on us.
 

It is by this light that we are enabled to identify and distinguish God's people and have fellowship with them, and by which we are enabled to identify and distinguish the world and avoid fellowship with them (Rom. 16:17-18; 2 Cor. 6:14-18; 1 John 3:13-14; 2 John 9-11). As the writer of Hebrews encouraged his readers to become skillful in the "word of righteousness" in order to "good and evil" (Heb. 5:13-14), we must continually preach the Gospel to the saved. God's people are commanded to speak peace where sinners believe THIS GOSPEL and give evidence of believing it. God's people are forbidden to speak peace where sinners do not believe THIS GOSPEL and give no evidence of believing it.
 

II. IT IS NECESSARY FOR WORSHIP(John 4:23-24; Phil. 3:3).
 

When believers meet together to hear the Word of God preached, to pray, to sing, to fellowship, our main goal is to worship God. True worship is the reasonable response of a redeemed, regenerated, converted sinner, to God the Father, through Christ, by the Holy Spirit. What is true worship? It is attributing unto God all those qualities of character revealed in our salvation based on the imputed righteousness of Christ. Some say that it is adequate simply to say, "through Christ," "in Christ," or "by Christ." We know that Christ alone is the center of our worship, and God the Father is the ultimate object of our worship. We cannot worship the Father except through the Son. But this does not mean Christ absolutely considered, or some mystical view of Christ. It is Christ our Great High Priest who satisfied law and justice on our behalf, and who enabled the Father to be just to justify the ungodly. We see God's redemptive glory revealed, not in Christ absolutely considered, but in Christ who satisfied law and justice and brought in the only righteousness which is the ground of our salvation and our worship.
 

Read Hebrews 4:14-16 - Prayer is an act of worship, and it based upon our Great High Priest and what He has accomplished that we come to worship. Christ's righteousness reveals the Father, because it is here that we see every attribute of the Father engaged on our behalf, honored and magnified so that we might come to Him, the Judge of all, and fully expect His favor based upon that righteousness alone. Christ's righteousness reveals the Son, because it is here we see Christ's glorified and exalted as our Mediator. It is here He comes to have the preeminence in our hearts. Without this, there is no worship, and we need to be reminded of this every time we meet together. We might compare it to God's glory in the Temple under the Old Covenant. Whenever they met to worship, it was always around the mercy-seat, based solely upon God's merit, goodness and mercy. When we meet together to worship, it should always be around our mercy-seat, Christ, based upon His merits, according to God's promise of salvation and final glory conditioned on Him alone.
 

III. IT IS NECESSARY TO BE ESTABLISHED WITH GRACE (Heb. 13:9).
 

The Holy Spirit's goal in our lives is to establish our hearts with grace, and the preaching of Christ and His righteousness is the only truth that will do that. The less believers hear this message and the less they are settled and skillful in it, the more they are apt to be tossed to and fro by every wind of doctrine. The more we see of Christ and our complete standing in Him, the more we will see the absolute certainty of our final glory based on His righteousness alone. Looking at ourselves, we cannot be established with grace. We must always cry, "O wretched man that I am." Our motto is "Blessed is the man to whom the Lord imputes not iniquity," knowing we have a righteousness that answers the demands of God's law and justice. Our motto is "God forbid that I should glory save in the cross of Christ." This is our comfort, assurance, and confidence. We must always beware of seeking to be established or seeking assurance of our salvation based upon things which God has excluded. Our minds are so affected by remaining sin and self-righteousness that we must be continually reminded that our final glory is sure and certain, not based on our efforts, and notwithstanding circumstances and outward appearance, but based solely upon the imputed righteousness of Christ. This forms the basis of true Christian obedience, character and conduct, and of the whole Christian life. Many claim that once we are saved we begin a race. This is true, but we need to know that this race is a race of grace, not legalism. We are to run the race being assured that we will finish not based on our running but based on the fact that our Great High Priest, our Substitute and Surety, the Lord Jesus Christ, has already completed the race and has assured us of victory.
 

IV. IT IS NECESSARY FOR MOTIVATION TO PERSEVERE AND OBEY.
 

The Gospel, wherein the mercy of God is revealed, is the main tool which God the Holy Spirit uses to motivate believers to persevere, obey, and perform good works (Rom. 12:1). All exhortations to obedience and morality and good works are to be motivated by this great Gospel truth of the certainty of our final glory based on the righteousness of Christ imputed. Even false preachers promote morality and works. What is the difference between a believer's morality and works and the false religionist's? It is the motivation revealed in this Gospel. Again, this is how we let our light shine, and this is how we are motivated to be ashamed when we sin. But it is ashamedness without fear of punishment which would set us trying to establish a righteousness of our own. This is how we are motivated to worship and obey God, but it is acceptable worship and obedience. Again, it is not because of any merit in the worship and obedience. We are still unprofitable servants in our own works. Again, it is acceptable for three reasons: (1) because it is performed by a justified sinner; (2) (2) it is the fruit of justifying faith; and (3) it is motivated by the certainty of final glory conditioned on Christ, to the praise of the glory of God's grace. Sometimes, because of the Scripture which we are dealing with at the time, we emphasize this truth more. Sometimes, not as much. But we must always make sure, when we are preaching obedience in any area, that our hearers understand that no obedience forms any part of the ground of our salvation and final glory. If we do not preach the Gospel while we are dealing in other areas of obedience, our sermons only become moral or psychological pep talks and not exhortations of grace.
 

V. IT IS NECESSARY BECAUSE OF OUR SPIRITUAL WARFARE.
 

The Gospel is the main weapon in spiritual warfare (2 Cor. 10:4-5; Gal. 5:17). The main issue in the warfare of the flesh and the Spirit which exists in every believer. This warfare is something in which the natural man by natural conscience does not and cannot participate. This is the warfare of justified sinners, and it mainly involves the Spirit of liberty in opposition to the spirit of bondage and legalism. The natural man does not have the Spirit of liberty. He only has the spirit of self-righteousness and legalism. Any obedience that is not motivated by that absolute certainty of salvation conditioned on Christ alone is legalism. But every true believer has remaining self-righteousness which constantly opposes the Spirit of grace and liberty. For this reason we must be diligent to make use of the means which God has given us to establish our hearts with grace, and that we may grow in the grace and knowledge of Christ.
 

This spiritual warfare does not exclude morality versus immorality because even true believers are subject to the passions of remaining sin. But immorality versus morality does not identify this warfare. The natural man by natural conscience conviction has these struggles. So even though it does not identify this warfare, it is included because we do not cease this conflict when God saves us. We are called on and commanded constantly to bring our character and conduct into conformity to Christ and not to fulfill our sinful desires. We are to fight these sinful passions with every fiber of our being and seek to be moral in thought, word and deed. But we are to fight those sinful passions in a different way, not by legal or mercenary motives seeking to remove God's wrath or to gain or maintain God's favor. So, the main issue in this warfare is the Spirit of liberty versus the spirit of bondage. The fact that we have these unlawful desires does not mean that we should doubt our salvation, nor be entangled again with the yoke of bondage.
 

That principle of bondage, of legalism and self-righteousness, constantly seeks to draw our minds to thinking that somehow, some way or in some degree, our salvation, our sanctification, our relationship with God, our fitness for heaven, is dependent upon or determined by our works and efforts at obedience. We desire never to have any thoughts of legalism ever again, even in temporal things, but this principle is still so powerful that we cannot attain that desire perfectly. Thank God that this self-righteous principle does not dominate our thinking and motives, and that it cannot overcome us, but it still influences us. Why not? It is because of the principle of grace and liberty which constantly seeks to draw our minds towards God in Christ, knowing that our salvation, sanctification, our relationship with God and our fitness for heaven, is totally dependent upon and determined by Christ and His righteousness alone imputed and received by faith. This principle of grace and liberty works by the Gospel and its particulars and implications to establish our hearts with grace. (Gal. 5:1)