Yes, but he's got the faith of a child. Simple.
5 seconds sound clip from the It's a Wonderful Life (1946) movie soundboard.
You can hear this line at 00:02:37 in the Blu-ray version of the movie.
Quote context
[...]
- That's why I came to see you, sir.
- It's that clockmaker's turn again.
- Oh, Clarence. Hasn't got his wings yet, has he?
- We've passed him up right along.
- Because, you know, sir, he's got the IQ of a rabbit.
- Yes, but he's got the faith of a child. Simple.
- A man down on Earth needs our help.
- No, worse. He's discouraged.
[...]