Well, all we can do is choose the denomination thats most faithful to the Bible.
So we decide what the Bible means? We decide whats true? Then the Bible isnt our final authority we are.
I don't believe for a second that this conversation actually happened. It's too canned. Right out of just about every "swimming the Tiber" testimonial.
Not to mention the inevitable logical fallacy embraced by the new convert: Churches B through Z all teach something different; therefore, church A is right. This ignores the possibility that church A is wrong too, and maybe church K is right.
Of course, if you call them on that, then circular logic kicks in. Church A is incapable of error; therefore church A is right.
It is odd that there is one God, one Bible (at least there is to a Christian) but so many different beliefs.
All of us want to know that we follow God's Word but as I see it, the only way to assure that is to follow His written word. Then you get into the different interpretations by different religions. Very confusing for someone. I've finally given up on "religion" and just study scripture. I listen to different teachers and the more I study the easier it is to weed out false teaching, according to His word.
That may not be the best way to go about it but I feel it has opened my eyes and ears somewhat and if I continue to study perhaps more will be opened to me.