That's a logical fallasy!

[robvalue]

You can't find the truth without proper logic. That is, you can't be sure you have the truth.

I'm not sure what alternate method you are suggesting? If someone is relying on a logical argument to make their point, and the argument is not valid, they have no evidence their point is correct. If they mean to demonstrate it is true some other way, such as an experiment or something, why are they making faulty arguments?

Without logic, you have nothing.

My name is rob. Therefore, God does not exist.

If that's all I've got, then I have an argument, it just doesn't make any sense and isn't worth anything. God may or may not exist, but I have nothing to demonstrate either possibility to be true.

So I'm not sure what your point is. If you're going to say faith... Don't say faith