Many today have been told, after they come to the Lord, that it is not sin to continue to live in a "marriage" with a person who is divorced from a former spouse who is still living.
They say that God forgives the past, and that we should remain as we are when God saves us. They base this reasoning on I Corinthians 7:17-24, which commands each one to "abide in the same calling wherein he was called." But notice that these callings mentioned have nothing to do with being in a state of sin. If a person has been living in sin, God expects that person to come out of that state of sin.