Whenever I think or discuss the great apostasy, I always think in my mind that of all the Christian groups it is the Catholic that is the strongest. Who else would have had the authority if not them?
I think I see that there is some acknowledgement in this conversation that some form of apostasy did occur. My understanding from my limited study is that the 12 apostles were killed...torturously I might add. And that the church was in a state of confusion for many years as HiJolly stated. I can't look at the Christian world today without seeing such variety in interpretation and doctrine. One builds a church on baptism. Another on tongues. And the list goes on. In my very limited missionary service to one state in the US, I spoke with many who had such differing views of the same biblical text. I was astonished by the variety of interpretations on the Nature of God question alone. And the last piece of this that still surprises me (and I don't know for sure if this is the Catholic position or not) is the decision that God no longer talks to man. That God somehow decided that he would let us interpret on our own. These ideas confuse me.
If God is the same yesterday, today, and forever then he must continue revealing his will. He literally led the Israelites every step of the way from Moses and Pharaoh and what Moses was to do with his staff, to telling the people to put lambs blood on their doorways, to giving the 10 commandments and to leading them to the promised land! And this is just one example.
It is clear that revelation was part of Jesus's mission after his resurrection for he met the twelve on the road and spent days and days with them. What was he saying if not setting the direction for the church to go forward with that very group of twelve that he so carefully chose and instructed before his death and resurrection. And also showing them his resurrected body so they would very literally be able to testify of the "good news"! How can one be a special witness of Christ without such literal and visual experience?
I ask myself now.....if I weren't going to be a LDS, where would I go? Well, the Catholic church would be my first stop.

Precisely because of the Peter/Rock/thing. But I stop in my tracks and ask where are the 12?
At the end of the day, I must conclude that either the Catholics got it right and the rest of the Christian world rebelled and went their own way OR a restoration was necessary. Not a new idea to my LDS friends here.......but something that I keep coming back to in my own searchings and questioning.
And such a question could be debated long into the night!

I am grateful, in this case, for the institution of prayer. I can go and sit alone before my maker and ask the question. Who of all these groups is right? And He will answer. I figure if anyone knows the answer, He does.