2 Corinthians 8:9-11 For ye know the grace of our Lord Jesus Christ, that, though he was rich, yet for your sakes he became poor, that ye through his poverty might be rich. And herein I give my advice: for this is expedient for you, who have begun before, not only to do, but also to be forward a year ago. Now therefore perform the doing of it; that as there was a readiness to will, so there may be a performance also out of that which ye have.

You are able but are you willing?

Matthew 21:28-30 But what think ye? A certain man had two sons; and he came to the first, and said, Son, go work to day in my vineyard. He answered and said, I will not: but afterward he repented, and went. And he came to the second, and said likewise. And he answered and said, I go, sir: and went not.

The lesson is about what you do in obedience of faith, not what your mouth speaks. But the key here should be the more important issue which is often overlooked. Both heard the request of the Father. Obedience of faith begins with hearing God. If you haven’t heard God, what are you doing?

God will cause you to be willing. How do I know this?

Isaiah 55:11 So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it.

I was tested many times before I understood. Why would God ask a son to do a thing if He already knew the son would not obey? So that the son would know his heart wasn’t right before God.

Jeremiah 17:9 The heart is deceitful above all things, and desperately wicked: who can know it?

God does.