I think it was... who said...

C.S. Lewis
G.K. Chesterton
John Piper
Billy Graham
Jonathan Edwards
A.W. Tozer 
Charles Swindoll
Martin Luther
John Calvin
Constantine
Augustine

“I think it was (insert any of the names above) who said... (now insert whatever wisdom you desire).”

There are people within genres, in the above case Christianity/Christian culture/theology, who hold enough influence and have such a depth of literary content which makes attaching a quote to them both weighty and useless.

I could say they same thing about the historians Herodotus, Xenophon, Livy, Tacitus or Suetonius.

Really, you just need to avoid outright foolishness. After that? You can say whatever your heart desires...