Question:I don't understand how a non-believer, who divorced their spouse for reasons other than fornication and remarries, if they are born again, are living in sin. I thought when you are baptized all of your sins were forgiven according to Acts 2:38. Are only certain sins forgivable? Can you give me some more clarification on this please?
You are assuming that the sin of adultery only occurs once when a person marries someone to whom they have no right to marry. What Jesus stated is that the situation is one that is adulterous. "But I say to you that whoever divorces his wife for any reason except sexual immorality causes her to commit adultery; and whoever marries a woman who is divorced commits adultery" (Matthew 5:32).
The Greek word moichatai, translated as "commits adultery," is a verb in the indicative mood (stating a fact), present tense (currently happening), middle voice (has been happening). Words in middle voice are harder to translate into English because our language doesn't have an equivalent voice. Jesus is stating that adultery occurred when they got married and it continues to happen up to the present time. In other words, it is an on going sin.
Baptism washes away sins (Acts 22:16), saves a person from sin (I Peter 3:21), and forgives sins (Acts 2:38), but it doesn't change the nature of sin. What was sin before doesn't become righteous because a person was baptized. If a person is a thief, he can be forgiven of his stealing through baptism, but it doesn't mean he can continue to steal because he was baptized. A person is committing adultery by being in an improper marriage. That sin doesn't suddenly become a non-sin by baptism. It would still be an improper, adulterous relationship after baptism.
There is also another problem that you are overlooking. Peter said, "Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit" (Acts 2:38). There are two conditions mentioned on the receiving forgiveness of sins: repent and being baptized. When a person remains in an adulterous relationship, where is the repentance?
So, you see that all sins are forgivable, but not all people are willing to seek forgiveness of all their sins.
Thank you for your quick reply. I was concerned because I am presently dating an individual who is a non-believer but is interested in the church of Christ. He has been married before and divorced his wife for desertion. I never question his privilege to marry. I always thought that because he was a non-believer his sins would be forgiven and he would be starting life anew when he becomes a christian. You have given me a lot to think about.
If by "desertion" you mean that the woman left him for another, then he does have a right to remarriage (Matthew 19:9).