A lady with a Baptist background asked me if I thought one sin would keep her from Heaven. She said "suppose a person was living in an adulterous marriage, but done everything else right such as attending church, studying the Bible, etc. Would this person go to Heaven?" Could you direct me to a similar question on your website or respond?
"If you really fulfill the royal law according to the Scripture, "You shall love your neighbor as yourself," you do well; but if you show partiality, you commit sin, and are convicted by the law as transgressors. For whoever shall keep the whole law, and yet stumble in one point, he is guilty of all. For He who said, "Do not commit adultery," also said, "Do not murder." Now if you do not commit adultery, but you do murder, you have become a transgressor of the law" (James 2:8-11).
The problem lies in the person's attitude toward God's law. A person who is willing to obey God in areas he agrees, doesn't care or finds it convenient to obey God, yet clings to a sin that he personally wants to commit demonstrates that his personal will comes before all others.
Christians do sin at times (I John 1:8-2:1), but they find all sin repulsive and work hard to overcome those sins. They understand Paul's words: "What shall we say then? Shall we continue in sin that grace may abound? Certainly not! How shall we who died to sin live any longer in it?" (Romans 6:1-2). This is not to say that if a Christian slips just before he dies that he has lost all possibility of reaching heaven. After all, "My little children, these things I write to you, so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous" (I John 2:1). Such would be a matter for God to judge. But no Christian should think that he can ignore his sins, continue to wallow in them, and then expect God to accept him anyway despite his sins. Christianity is about battling sin, not compromising with the enemy.