Sure as God made little green apples phrase informal
Meaning absolutely certain or without a doubt
I am as sure as God made little green apples that three is the right answer for that Math question.
Peter is as sure as God made little green apples that he's doing his task the right way.
That's absolutely right.
Totally certain.
With absolute certainty; decisively
You can be absolutely certain that something is true or will occur.
“Little green apples” has become the more popular form of the phrase which has several vesions such as as sure as God made apples, and the good Lord made green apples. A source said that the idiom "As sure as God made little green apples” has been cited in print since the 19th century.
A humorous way of saying that what one has said is just what they acknowledge and may not be entirely accurate
Mike: Have you returned from your vacation on the beach? Your skin seems to get tanned.
Jenny: My skin is always dark. That's my story and I'm sticking to it!