1 Peter 1:14

14 As obedient children, do not be conformed to the former lusts which were yours in your ignorance,

As Christians we must be obedient to God. That is our calling and it should be our desire—to please Him in everything. Before we were believers we followed our own desires (our lusts). That is all we knew. We had no other direction in life. The world, and our flesh, is all we knew. God and Jesus were alien to us.