B.: Of course!
P.: So do I. But can you give me a single Bible verse which all by itself establishes that God is Triune, or that Sunday is now the Sabbath?
B.: No, I must admit that I cant think of any such texts right now. But if we take the Bible as a whole, it is very clear that God is Triune and that Sunday is now the Sabbath.
P.: Exactly! And precisely the same applies in the case of infant baptism. But tell me — does your Church allow its women to celebrate the Lords Supper?
B.: Of course!
P.: So does the Presbyterian Church. But where in the Bible do you read that any women ever participated in the Lords Supper?