In our culture it is very easy to covet what our neighbors own. We live in a culture that lives in materialism. It destroys our joys and our desires to give to others. We have so much and have no little joy.
Marriage was created by God for partnership, intimacy, and being a team together. God's plan in Genesis was that the husband (and Wife) would leave their father and mother and be joined together with their spouse. Leaving is so important in creating a healthy marriage. God wants the marriage commitment to be pure and clean.