Matthew 7:15-27 15 “Beware of false prophets, who come to you in sheep's clothing but inwardly are ravenous wolves. 16 You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles? 17 So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. 18 A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. 19 Every tree that does not bear good fruit is cut down and thrown into the fire. 20 Thus you will recognize them by their fruits.
21 “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. 22 On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ 23 And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’
24 “Everyone then who hears these words of mine and does them will be like a wise man who built his house on the rock. 25 And the rain fell, and the floods came, and the winds blew and beat on that house, but it did not fall, because it had been founded on the rock. 26 And everyone who hears these words of mine and does not do them will be like a foolish man who built his house on the sand. 27 And the rain fell, and the floods came, and the winds blew and beat against that house, and it fell, and great was the fall of it.”
Those Christ says He never knew DID appeal to their works. Obviously their works didn't save them.
So that verse can't be used to support your claim.
1 Corinthians 6:9-11 9 Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, 10 nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God. 11 And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.
There were that no longer. They got saved out of that lifestyle and were saved. That doesn't mean that a believer who happens to fall into sin isn't saved any more. It's referring to unbelievers who are living in those sins. So that verse doesn't apply to support your contention either.
John 20:21-23 [Jesus] said to them again, “Peace be with you. As the Father has sent me, so I send you.” And when he had said this, he breathed on them and said to them, “Receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained.”
1 John 1:7-10 7 But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin. 8 If we say we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. 10 If we say we have not sinned, we make him a liar, and his word is not in us.
Believers sin and provision is made for forgiveness. There is no provision for retaining sin and it doesn't affect one's salvation. If it did, it would reduce salvation to being based on works. If you're good enough, you get in. If not, too bad for you.
If you don't get saved by works, you don't stay saved by works.
Galatians 3:1-10 O foolish Galatians! Who has bewitched you? It was before your eyes that Jesus Christ was publicly portrayed as crucified. 2 Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith? 3 Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh? 4 Did you suffer so many things in vain—if indeed it was in vain? 5 Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith— 6 just as Abraham “believed God, and it was counted to him as righteousness”? 7 Know then that it is those of faith who are the sons of Abraham. 8 And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.” 9 So then, those who are of faith are blessed along with Abraham, the man of faith. O foolish Galatians! Who has bewitched you? It was before your eyes that Jesus Christ was publicly portrayed as crucified. 2 Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith? 3 Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh? 4 Did you suffer so many things in vain—if indeed it was in vain? 5 Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith— 6 just as Abraham “believed God, and it was counted to him as righteousness”?
7 Know then that it is those of faith who are the sons of Abraham. 8 And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.” 9 So then, those who are of faith are blessed along with Abraham, the man of faith.
10 For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.”
Let us look at those verses in context indeed. The very verses that you posted show that faith alone is not enough. Did you miss this part:
Beware of false prophets, who come to you in sheep's clothing but inwardly are ravenous wolves. You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles? So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus you will recognize them by their fruits.Or:
Everyone then who hears these words of mine and does them will be like a wise man who built his house on the rock. And the rain fell, and the floods came, and the winds blew and beat on that house, but it did not fall, because it had been founded on the rock. And everyone who hears these words of mine and does not do them will be like a foolish man who built his house on the sand. And the rain fell, and the floods came, and the winds blew and beat against that house, and it fell, and great was the fall of it.Faith alone, or crying out "Lord, Lord" is not enough. We must produce good fruit (good works) and do what our Lord commands.
They got saved out of that lifestyle and were saved. That doesn't mean that a believer who happens to fall into sin isn't saved any more.
And what happens to those who believe but continue to live in sin?
Believers sin and provision is made for forgiveness.
Yes, indeed. Notice that the passage that you quoted indicates that salvation is not unconditional based on faith alone:
But if we walk in the light…There is no provision for retaining sin and it doesn't affect one's salvation.
If we confess our sins…
Really?
Receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained.If you don't get saved by works, you don't stay saved by works.
10 For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.”
Again, "works of the law" and "the Book of the Law" refer to the Torah or Law of Moses.