I run across it all the time—christians who speak of a particular sin that doesn’t personally beset them, and declare that whoever commits such sins regularly, without constant repentance (be it drunkenness, adultery, homosexuality, lying, or spreading rumors about Sister So-and-So), will not make it to heaven.
When the christian makes such assertions, he actually believes that nobody can make it to heaven. If one who is born again must stop sinning to maintain his salvation, then nobody can be saved, for the law of the flesh remains in all humans alive on this earth (Romans 7:23).
A big reason for this flawed understanding is the deficiency of most English translations of scripture in which several different words with different meanings all got translated as “sin” or “sins.”
1 John 3:9 says that one who is born again will not commit sin. But, what many christians fail to understand is that the sin referred to there is the sin of unbelief only—which is the singular sin that condemns (John 3:18, Hebrews 3:19). Since saving belief is defined by having the Holy Spirit, and He is an eternal seal on the bride, those who have the Spirit cannot, by definition, be in the singular condition that condemns (hamartia = a dead spirit = the sinful condition of unbelief).
Once one has been indwelt by the Holy Spirit (which is to be given saving belief), it immediately sets up a battle between the flesh and the spirit. Those who do not have the Spirit do not have the battle. They are ruled by their flesh alone. But, those who have the Spirit will always have to struggle against their flesh and its sins.
Notice, though, that the issue pertains to those WHO HAVE THE SPIRIT. That should end the discussion, for those who have the Spirit have the Son (Romans 8:9), and those who have the Son have eternal life (1 John 5:12). Period. End of story.
There is no other evidence needed. Nothing about the way one lives is evidence of whether he has the Spirit of Elohim. What did David do while he had the Spirit? What did Samson do while he had the Spirit? The only evidence that can be seen by other humans is of sanctification (holiness), not justification (righteousness).
Those who say that if one commits sins of the flesh, it is evidence that “he was never saved to begin with” better hope they’re wrong, for they, too, commit sins of the flesh, so their false assertion would keep them from heaven as well. Chances are, such a person doesn’t really know what it means to be born again in the first place, since christianity teaches a false form of salvation that is declared by man’s own decision.
Often, it’s the sins with which a christian doesn’t struggle that he condemns in others, while he turns an understanding eye away from his own sins. That’s the “log” Messiah spoke of. If your form of belief is primarily concerned with the fleshly sins of others, then it’s not saving belief you have, but the condemnation of the Pharisees.
For more information: Do Sinners Go to Heaven?