Giving of your Tithes and Offerings is a command of God. As we read scripture, we see that Abraham in Genesis 14, gave a tenth to Melchizedek, the High Priest as an act of worship unto God. This even pre-dates the law. Reinforced in Malachi 3, we understand that this act of worship is attached to blessing and cursing. If we want to live a blessed life, then we are to be obedient to God with our finances, especially in giving of our tithes and offerings. Malachi 3:11 says, "He will devour of the enemy for our sake."