Dear Brad C.,
"Basically, to me the truth is that God gave his only son so that we as sinners could be forgiven for our sins and join him in Heaven."
First, I'd say that you know this truth because of the Catholic Church. ;-)
Second, I'd also note that there is nothing about Masonry that requires you to believe this absolutely fundamental truth. It is the essence of Divine revelation. And it is entirely disregarded, at least in principle, by Masonry.
And that is one of the problems that the Catholic Church has with Masonry, that it teaches part of the truth about God (from natural revelation), but not the other part of the truth about God (from Divine revelation).
"The fact that I believe I can do this outside of the RCC seems to bother them."
Then your perception isn't quite correct. The Catholic Church rejoices that folks know about the salvation of Jesus Christ. She only mourns that non-Catholics don't have the fullness of grace that comes from perfect communion with Her. She is, after all, in Her own understanding, the Body of Christ.
But we're getting far afield.
The Catholic Church would be less distressed with Masonry if it were to properly and positively affirm the Divine revelation of Jesus Christ.
sitetest