Ephesians 1:19 ends with the line "according to the working of His great might." This is after Paul tells the saints at Ephesus he prays for them without ceasing and then tells them how he prays. I read this phrase a few times and didn't really understand what it was referring to. What was "according to the working of His great might,"? These really long sentences, which I believe Paul should be famous for, are sometimes hard to follow for me. Verse 16-23 is all one sentence. But that's what's great about doing a study of scripture where you don't limit the minimum length of a passage you look at.
That was a lot of setup to say, I finally realized this phrase was connected directly to the previous word. I was too busy looking for a connection to a phrase or the whole prayer that I missed seeing the word "believe". And, so often, we associate the word "believe" with something we do/did. We didn't do it. Our belief comes from "the working of God's great might." To pull a sinner out of sin, it took God's great might. It took God to save us from our sin. He caused us to believe. Because without Him, we wouldn't have chosen Him. We would choose the easy path, sin. We are so blessed, we who are called, by that calling from Him who called us, according to His will, according to His might.
Praise God for His Great Might.