One cannot lose one's Salvation. Salvation is a done deal and as a gift of God is without repentance.

But, David wrote in the Psalms, If I regard iniquity in mine heart the Lord will not hear me. Some that have made a profession with their lips do not possess Christ in their hearts because of their unwillingness to give up the sins God tries to reveal they are holding on to. They love the sin more than the Savior. Jesus wants the preeminence in man's life. He is not willing to share you with satan any more than you would want to share your wife with another man.

The rich man went away sad... not because he was rich, but because of his love for those riches. Sin separates man from God.

God knows our hearts. He knows the hidden things of our hearts. That which we are unwilling to quit when His Word and not just His Word, but His Spirit tells us it is sin.