If a person is living in sin, that person is lost. No matter how many aisles he walked, no matter how many preacher's hands he shook, no matter how many times he got baptized, no matter what he did or what he claims. If he is living in sin, he is lost. A Christian may fall into sin, but he will not live in sin. For now we live, if ye stand fast in the Lord.
Christians continue in the faith.
Those who are born again go on, thick or thin. They don't turn back. The salvation package comes with this teaching. The same grace that saves, teaches. The faith that comes by hearing the Word of God is tried, tried, and tried again.