Paul reminds us in 2 Corinthians 9:7-8 to let each one give as he purposes in his heart, not grudgingly or of necessity; for God loves a cheerful giver. And God is able to make all grace abound toward you , that you, always having all sufficiency in all things, may have an abundance for every good work.

Giving glorifies and honors the abundant generosity that is given to us by the Father and so in response to His generosity, we reflect it back toward Him.