Jefferson believed Jesus was a great and wise man. But this quote was in context of attacking Christianity as generally practiced, especially when embodied in organized religions.
The Bible is the cornerstone of Liberty. - Thomas Jefferson ... It is impossible to rightly govern the world without God and the Bible. - George Washington
There is no evidence that either of these men said these things. The quotes are most likely made up or misattributions (the first one is also often attributed to Samuel Adams).
Some other quotes from God from jefferson have also been posted on FR. as well.
Your saying they did not say these things is not really an expert witness on the subject.
So they will stand as is.