Hi total relism

I think you will find it helpful to read the book first.

It is hard to answer your question without knowing a bit about you - are you a Christian yourself, and which type of church do you belong to?

However, a quick answer would be that Lewis was writing/speaking about Christianity - not a church and its practices or doctrines.

On the Lewis website "Into the Wardrobe", here is a description of this book:

"Mere Christianity"
New York: MacMillian, 1943.
This originated as a series of fifteen-minute radio talks addressed to a very general audience, undertaking to give a general account of Christian belief. It begins with a discussion of some reasons for believing that God exists, and why it matters that He does, and then continues with an account of the redeeming work of God in Christ. It includes a discussion of Christian moral standards, and Trinitarian theology. Throughout, the author undertakes to confine himself to the common Christian core of belief, and to steer clear of disagreements between denominations -- hence the word MERE in the title.

i am christian and protestant, i am learning currently catholic teachings. Some say they are saved some dont, some teach salvation by faith plus works etc. So i was just interested in what lewis thought was common to both catholic and protestant and his opinions on tolkien's faith as well.

I would highly encourage you to read the book if you haven't started already. I think you'll get lots of questions answered that way. Lewis does a great job at explaining Christian concepts in an intelligent way that the common man can understand.