Why God uses people to do his will

In her daily WEI email to teachers, yesterday Jan Towell asked for input on a student’s question.

The student acknowledged that God is omnipotent and that he caused a virgin to give birth to a boy. Then he asked why God uses people to accomplish his will instead of doing it himself directly.

I replied with the following answer:

This is a part of the fellowship that God creates. He uses people to accomplish great things because it involves others in his great plan. This is a great privilege. God allows us to work together with him. We not only enjoy his blessings, in Christ, but we also enjoy working with him to bless others. “Faith working in love” is what God does and what he calls us to do also, Galatians 5.6.

What might you add to enrich this student’s understanding of why God uses agents to perform his great works?