I suggest you actually see the Catholic rite of Baptism. You are not baptised into a Church, but when you are baptised you become a Christian. There is only one Christian Church the Catholic Church.
classy:
If you read the WT literature on baptism, you will find the same claim about how you "become a Christian." But in both churches, Catholic and JW, there is doublespeak. The true intention of baptism in both organizations is to make you a member. The publication I quoted from is ©1981 by John A. Hardon, S.J., and bearing the Imprimi Potest, the Nihil Obstat and the Imprimatur, the official marks of the Roman Catholic Church. These indicate a book accurately portrays RC doctrine and is therefore suitable reading for members of the RC Church. It clearly says "One cannot cease to be a Catholic because, once baptized, he cannot be un-baptized." So, why deny that Catholics understand baptism to be baptism into Catholicism? Your argument is evidence that, just as JWs claim about themselves, Catholics claim to belong to the only true church.