"It is more blessed to give than to receive."
Who said those words?
If your answer is "Jesus," how do you know? That sentence is not written in any gospel. Even the person quoting those words had no direct knowledge that Jesus said them. But does it resonate with Jesus' teachings?
Should we believe those words? Can they be tested? In fact, they can- and we know them to be true.
The quote above is from the book of Acts- quoted by Paul, recorded by Luke. Paul had not heard it himself, he could not have. He did not become a Christian until after Jesus died, and he was violently opposed to Christians before his conversion. Yet he quotes those words and credits them to Jesus. They must have been taught to Paul. Maybe he heard them from someone he trusted, or perhaps from several different sources.
If Paul had been more of a skeptic, or worse, a cynic, those words would never have become a part of Scripture, and we would all be poorer for it. Is that not the quintessential Christian experience? We hear what we cannot know for sure, and make room for it, and accept it. If we can convince ourselves- that is great. If we can convince others- that is even better.
Had Paul not believed what he had heard and shared it with others, we would never have that rich piece of spiritual treasure. Better that it seems to have originated with Jesus than anyone else. When you think about it, we are fortunate it was attributed to him first.