Faith does not mean just believing stuff to be true.
Faith requires obedience. Faith = faithfulness.
Believing that Jesus died for your sins does not do you one bit of good unless to follow up that belief with a commitment — one that you stick to — to spend the rest of your life obeying Jesus. That commitment amounts to an oath of fealty, of loyalty for the rest of your life. You have become enrolled in the ranks of the king. No other king can claim any part of you because you gave it all to Jesus. Forever.
No turning back. No turning back.