God owns everything
Everything we have belongs to God and He has entrusted us to be good stewards. It is a privilege to be God's instruments on earth and distribute His resources to a broken, hurting world. When we give we are actually making a conscious decision to exchange our plans, agendas and priorities for God's.
How we handle our money and possessions shows how fearlessly we abide in Him.
Jesus talked more about money than virtually any other subject in the Bible. He said, "Where your treasure is, your heart will be also" (Matthew 6:21). That means we declare something to be truly important when we invest our money in it.
Giving grows our faith.
Giving demonstrates our faith that the God who has provided for us in the past will provide for us in the future. It's the opposite of fear. Fearful people hang on with white-knuckles to anything they can get. Faithful people see everything in life as a gift from God - including their money. Every time we open our hands in generosity, we are saying to God, "This is yours anyway - please use it for your purposes."