One problem that Catholics see with other religions is the lack of Tradition. With out Tradition it is really easy to take versus from the bible out of context. Religion can be thought of as an oak tree. Catholicism is the roots and the trunk of the tree. All other religions stem from Catholicism as branches and twigs.
Some branches are stronger than others depending on how close to the trunk they are.
Others are weak and fragile and far away from the trunk. The closer to the trunk a branch is the older and more stable the branch is. If you will, the more tradition and maturity the branch or Religion has. Being the last apostle of Jesus Christ, the revelation was completed. Everyone who had talked and been exposed to Jesus was now gone.