I went to BYU with a lot of college credit already, which meant that I wasn't taking a lot of generals, but was in my program earlier and taking higher level courses with mostly return missionaries.

One of these courses was "Philosophy of Religion", wherein the professor on Day 1 presented us with Anselm's ontological proof of God on Day 1.

Namely that God is defined as a being above which nothing greater can be imagined. And that anything conceived of in theory, would be greater if it were made real. And since the theory of God exists in the mind, then we can imagine something greater (real God) which would contradict the definition of God. Therefore God must exist.

I have a number of issues with this proof now, but at the time I pointed out that we, as a religion, believe in multiple gods, that we can all become gods. Therefore the initial definition (God = that above which nothing can be imagined) doesn't apply and the proof falls apart. That this proof of God doesn't apply in an LDS context

The response to me mentioning this was both immediate and overwhelming from both the professor and many well-meaning RMs who proceeded to earnestly testify to me that they KNOW there is a God and that I too can know of a surety.

As much as I tried to clarify that I was not questioning the existence of God, simply the validity of this particular proof (and I was 19 at the time so may not have clarified as well as intended), the whole time turned into making sure I knew there is a God and that he loves me personally. Lots of people telling me I needed to find out for myself before I go on a mission the next year