Unconditional Security Teachers are wasting time preaching the gospel according to their theology. Why? Because they could be preaching the gospel to someone who once had a true moment of faith. Here is the catch. They have no way of knowing that. But Jesus said you can know
For one to say a professing Christian who turns to open sin was never saved is also to deny that we can know who is saved and who is not by their present tense behavior.
Matthew 7:16-17 KJV Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? 17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.
1 John 3:7-8 KJV Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous. 8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
1 John 3:10 KJV In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother.
1 John 2:3-4 KJV And hereby we do know that we know him, if we keep his commandments. 4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
Matthew 7:16-17 KJV Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? 17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.
When news of this reached the ears of the church at Jerusalem they saw evidence of the grace of God. According to OSAS people you wouldn't be able to tell if they once had a true profession of faith.
Acts 11:22-24 KJV Then tidings of these things came unto the ears of the church which was in Jerusalem: and they sent forth Barnabas, that he should go as far as Antioch. 23 Who, when he came, and had seen the grace of God, was glad, and exhorted them all, that with purpose of heart they would cleave unto the Lord. 24 For he was a good man, and full of the Holy Ghost and of faith: and much people was added unto the Lord.
To say a professing Christian who turns away from his profession of Christ to wickedness was never saved is to deny that others were ever able to spiritually identify him. True Christians can and do, at times, fall away and according to Jesus they are spiritually identifiable.