The 16 expressions of forgiveness

The thing with comparitive religion is like this. Scholarly discipline dictates a certain cold intellectual detachment from the subject you're studying whereas religion dictates a very strong attachment to the subject. 

So, there are two negatives. Watering down your Judaism and allowing a place in your heart for beliefs that actually contradict your own.

First, it will demand of you to detach yourself from your belief in order to properly compare Juidaism to other religious without prejudice. This can only water down your regular thought paterns about what you believe in, when you think regularly, "let's place these ideas from these religions on the same level so we can compare them properly." The reality is that we "believe" that our religion is divine while the other is not. So once you end up saying to your self, "If I say for a moment that Judaism is not true, the same as this other belief, what is equal between them and what is not."

On the other hand, when discussing other religion, there is the demand to truly understand it and it's pathos, so to see it from their perspective you say to yourself, "let's see it through their eyes. What is it like to believe this as true as they do." In this case, instead of the cold detachment a believer in Judaism should have to these conflicting beliefs, you have opened yourself up to literally thinking thoughts of avoda zara to properly understand and  write about the subject.

The goal should be then, if you're going to do this, to stay devoted to Judaism in your heart with an emotional belief and devotion while, at the same time, treat the other beliefs that you are studying with the intellectual detachment of a scholar.

In addition, I'll reiterate what the Rebbe said to people who were studying secular subjects. As you increase the secular knowledge you should increase your Torah study at the same rate or greater in response.

Going in to a place of worship etc snd the negative or positive emotions it evoks is also important but recognize please the fundamental shift in judgment this discipline demands on you.