In Deuteronomy 6, the Shema is followed by v'ahavta saying that God is one and we should love Him. This is a radical departure from the prevailing polytheism in the rest of the world. Other 'gods' are transactional. If you need rain make a sacrifice to the rain god; otherwise you don't care about it and it does not care about you. Our God, on the other hand, desires to have an ongoing relationship. That relationship is based on mutual love and affection.