In another dispute with his people in Malachi 3:6-12, God gave his people of that day a lesson in generosity, which Christians need to learn as well, especially as it has been transformed by the coming of Christ.
Although it is impossible to say what is the best thing about being a Christian, the theme of Galatians 4:1-7 is an excellent candidate...
Although the nations are constantly in rebellion against the Lord, he has established his Son as King over the whole world.
When our life is off center, the result is dissatisfaction. In Haggai 1:1-11, God calls us to center our lives on him.