"Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver." II Corinthians 9:7
A mother wanted to teach her daughter a moral lesson. She gave the little girl a quarter and a dollar for church and said, "Put whichever one you want in the collection plate and keep the other for yourself," she told the girl. When they were coming out of church, the mother asked her daughter which amount she had given. "Well," said the little girl, "I was going to give the dollar, but just before the collection the man in the pulpit said that we should all be cheerful givers. I knew I'd be a lot more cheerful if I gave the quarter, so I did."
What a privilege to give to the Lord, and give to the work of the Lord. Being able to give to God Almighty is an incredible thought. He doesn't need it, He doesn't beg for it, we simply find incredible joy by honoring Him. I think the cheerful part is how thankful we are for being able to give. I am sure you have heard people say, "But I earned it". Yes that may be true, but the joy would be in how thankful and grateful we are for the abilities that He created in us.