Backslider's

Luke 9:59-60 "And he said to another, follow me. But he said, Lord, suffer me first to go and bury my father. 60 Jesus said to him, let the dead bury their dead: but you go and preach the Kingdom of God."

Most likely this man was a false convert, a backslider, but most likely he just never slide forward in the first place; however, a true convert not only sticking his hands to the plought he doesn't look back or go back.
Luke 9:62"and Jesus said to him, no man, having put his hand to the plough, and looking back, is fit for the kingdom of God.