distracted,
I investigated this very topic a number of years ago for some of the same reasons you have put forward here. What I am saying is off the top of my head and I can’t remember sourses very well either. I know that I was satisfied that the Holy Church teaches the truth and is not saying different things about this topic.
One problem people run into is what do we mean by “the Church”? One of the posters had a relevant quote from Lumen Gentium. The “Church” is not just the Roman Catholic Church. It includes all christians. There are even ways for non-christians to go to heaven. The faith is meant to lived out in a community of believers, and it is impossible to be a christian without the Church. For one thing we need the sacraments, and the ministry of the priests, we need teachers, and all that. Oh, and most importantly, we need the Head.
Then you have what Jesus said, we need to do the will of the Father. Love God, Love your nieghbor, Do good, avoid evil. We need to believe in Christ as lord. All these things are marks of the Church. So a person who holds these things to be true but is not yet baptised physically, can still go to heaven by virtue of desire.
There are means available known only to God for a soul to go to heaven we have figured out a number of them but we have not exauhsted the list. Only God will judge in the end, and only God knows the heart. Technically, even a pagan can attain heaven, under the right circumstances. There is a good discussion of this in one of Pope John Paul II"s letters. I can’t rember the name of it. It came out about 8-10 yrs ago and was about salvation is only thru Jesus Christ.
I am sorry if I am being more confusing than a help, the catechism has very good information on the whole topic too. The paragraphs on Baptism, Holy, Catholic, Apostolic Church all go into the details of what and who is the Church, why and how she is needed for salvation etc.
Peace,
Tom