Isaih 57-15 states that God will revive the one who is humble,  The enemy of humility is PRIDE. Leaving GOF will make you " Prideful". If you have wandered awat from God aka " Back slidden" God is still ,arried to you . HE still loves you and wants you to tryutn to HIM. Your mistakes don;t matter , even your recent sins done a few hours ago. Ask HIm to take you back and all will be forgiven.