Israel never actually abandoned the God of Abraham, Isaac, and Jacob. Their problem was not replacing Yahweh with other Canaanite gods. Their problem was setting other gods beside him. Yahweh remained their national deity, the one on whom they called when it came to war and threats from enemies.
You are not a sinner merely because you do sinful things. Though that's true. You are sinner in the first place because from the moment you were conceived in your mother's womb, you were bent in the wrong direction (Psalm 51:5). That is, your heart longed for the same independence from God that Adam and Eve pursued when they ate of that stupid fruit in the garden. You've inherited their rebellious heart and attitude, and not only that, if you were honest, you would admit that you have actively invested a lot of your time and energy into cultivating that rebellion.