Maybe it's no surprise to you that it is only God who can work in you. But have you considered how far that goes?
Not only is it Him who works in us, but it is Him who gives us the desire to want to do His will and to carry it out.
So you see, we don't do anything in our own strength when we remain in Him. It is Him who fills us with the compelling and the execution.
Seem too simple? Because it is! Sometimes we overcomplicate God's simple Truths.
Walk in what He has for you, and feel His pleasure.