I would love to attend Mass but...
... I'm not Catholic. Never been a Christian in my whole life. But I'm enchanted by the Sermon in the Mount, and as I listened to Christian chants in YouTube, I was moved to tears. I don't know why.
My town has two churches, one Catholic, one Protestant. Did a research and decided that the Catholic church makes more sense to me, I can tell you the reasons if you like.
So, I don't believe in an almighty, eternal God, nor in souls, demons or whatever. I don't know if I'll believe in these in the future, either. But I feel this weird pull.
Can I come? Would the presence of, well, technically an unbeliever bother you?
. . .
EDIT: Thank you all! Boy, if only people in life were so welcoming as all of you who commented.