"Can two walk together, except they be agreed" (Amos 3:3).
It would be conflicting if your belief doesnt match the other. It only ends with someone compromising to keep the other happy.
All my friends are christians, this helps with my walk.
But there are associates and then there are bestfriends. I have associates who are not living as they should. I'm not in constant fellowship with them, but when we meet it's my job to convert them.
As for a fool.
The fool takes no pleasure in understanding, but only in expressing his opinion (Proverbs 18:2; RSV)