God is generous and so he calls us to be as well. What we do with what God has given us shows the world where our hearts are at and helps proclaim the gospel.
In a very real sense, God doesn’t need our money. According to Him, everything we have and everything on this planet already belongs to Him. Giving back to God a portion of what He has given us is an act of faith. It’s a decision and habit, on our part, to express gratitude for what God has given us and to express in a tangible way our dependence upon Him.