While "unjudge" isn't a commonly used word, it makes sense semantically, meaning "to not judge."
Here are some other options that convey the opposite of judging:
* Disregard: To pay no attention to
* Overlook: To ignore or not notice
* Accept: To acknowledge and embrace without criticism
* Tolerate: To allow or endure without disapproval
* Empathize: To understand and share the feelings of another
* Forgive: To pardon or cease to hold a grudge against
* Applaud: To praise or express approval of
The best choice will depend on the specific context in which you want to use it.