The real danger in this whole discussion is reducing Catholicism to some theory of creation that we’re trying to intellectualize conceptually and abstractly. I will be the first to admit that I am not a big fan of the new Catechism - I am even less of a fan of the new RCIA process. The problem is not in the truth of it, but rather in the size and complexity of it. Readers get lost in a maze that puts many to sleep along the way. The much shorter and to the point Baltimore Cathecism was equally valid, but more successful in getting through to the readers. One of the problems I really have with the new one is the over-reliance on philosophy and theology, making the presentation almost a legal argument intended to sway potential believers into a set of beliefs rather than an exploration of reality to uncover reality.
The other religions are just that - religions. Once humans scattered around the Earth they knew they couldn’t explain how the Universe came into being, and no one in the Day of Abraham but for Abraham himself could “get it” the way that Adam once knew God. So these competing intellectual theories became a human sport, but in the end, none actually defined God nor had any chance of altering God’s reality. What we are left with are words, if even the Word. I submit that for many reasons on many levels, the Sacred Scripture is not a convincing argument - standing alone, and I’m actually writing a book on this.
So what is it that the other religions lack that Catholicism gives? God Himself, through the Holy Spirit is available to us, and it through receiving the Advocate, this Fire of God in our hearts that we come to know what is fact and what is fiction. We can’t prove anything to the Budhists, Shinto, Pagans, Muslims, or Hindi who do not recognize the Holy Spirit. It is because they are not sharing this experience with God that we can through our Sacraments, and thus to argue about God with any of them would reveal both sides to be foolish. All we can do is pray for anyone reduced to questioning which religion is best so that they may, through the same Holy Spirit that spoke to the Prophets and to John the Baptist and to the Apostles and to Catholics today, be lead to hear His voice today, and harden not their hearts.