God created a world in which we cannot create or destroy matter. All we can do is change matter. We make out of what God created. God created out of nothing.
God created the world and everything in it. God created human beings, men and women. God gave us this world. God gives us faith, forgiveness of sins, life, eternal life and salvation. God gives us gifts of talents and abilities to work. God makes sure we have a job to work. God gives us the ability to work to make a living, to earn money (our means of barter) to feed, shelter, and cloth our families. God gives, and we are given to.
Now, if God can do all that, what is to keep Him from keeping His church going? If everyone in church stopped giving, do you think the church would cease? If all the “best” givers moved away, do think the church would close? Certainly not! God is the one who keeps the church going. God is the one who makes sure the church stays open and continues to do His work.
Why the giving? Why the First Fruits, Tithes, and Offerings? Because of our need to respond to God’s good and gracious giving. Because of our need to in some small, insignificant way, say, “Thank You Lord!” To God be the glory.