Keep his word insde.

Thy word have I hid in mine heart, that I might not sin against thee.

Psalms 119:11

We always, as children of God, need to keep his teachings with us at all times. We have to hold on to what God has done for us. We may not lose our salvation, but that does not mean pur heart can't turn from God. We can lose to sin if we are not on gaurd at all times. We must memorize verses and keep growning in the faith.