Young Han in the Clone Wars could be done well (by someone else) he could be sceptical of the Force because it didn't help stop the countless deaths of people (including many Jedi) during those wars.

He might even have started off believing in the Force but after seeing the bloodshed became a hardened cynic.

Imagine Empire Of The Sun but on Kashyyyk, with young Han watching the Wookiees and Jedi fighting the droid armies only to have their own troops turn on them and enslave his Wookiee friends.

I can't imagine Lucas pulling that off though.