Christians are more like the Avengers than Superman. We're not self-sufficient lone rangers. We're a group people with major issues who together, by God's grace and power, can be changed and can change the world.
As Christians, we believe we are the recipients of incredible, undeserved generosity from God. He hasn't treated us as our sins deserve - but has poured out his mercy and kindness to us - and continues to do so every day!
One of the ways we respond to God's generosity is to give our money cheerfully and sacrificially to honour God, and make Him known.