What we do with what God has given us shows the world where our hearts are at and helps proclaim the gospel. We want to glorify God with every area of our lives, and that's including our finances.
Giving is one of God's principles, and has been around before the law and remains after the law.
Tithing = Removes the Curse and turns on the Blessings. This must be done first, before any other giving or your giving is cursed.
Alms = "Giving to the needy and poor" shows God your not stingy and love others. (Must be done in secret to protect their dignity.)
First Fruits = "Giving God all of the First Increase that comes in." Shows God he can trust you with increases and therefore He gives extra blessings to your money with more increases.
Offerings = "Seed" givings or plantings, up and above the tithes. When given or planted in good ground, it returns a thirty, a sixty or an hundred fold return. This is how you get out of debt biblically. You give your way out. God cannot be out-given, He will repay.