Just because someone invites doesn’t mean one is obliged to go…and why would they invite if not to evangelize you. If you invited a non-Catholic to Mass wouldn’t that be your hope? That they would be drawn into what we believe is the truth? It they see you are interested enough to come, they can talk more about it, and give you more literatures…little steps to a goal. Your curiosity could lead you astray and into confusion, and to a gradual erosion of faith.
The Bible warns us:
“Have nothing to do with the pointless philosophical discussions and antagonistic beliefs of the ‘knowledge’ which is not knowledge at all; by adopting this, some have gone right away from the faith. Grace be with you.” [1 Timothy 6 20-21]
“The time is sure to come when, far from being content with sound teaching, people will be avid for the latest novelty and collect themselves a whole series of teachers according to their own tastes; and instead of listening to the truth, they will turn to myths.” [2 Timothy 3:3-5]