There are basically two views on baptism (with lots of different permutations). One is that it is a symbol, something we do in obedience, to show that we receive Christ's grace and mercy. For people who believe that, it is indeed "a wonderful expression" and that "you should believe before being baptized." Thus, they tend to baptize adults, or children who are old enough to understand the Spirit's work in them to draw them into faith. To them, re-baptism isn't anything strange, because they see it as an act of obedience. Some of the members of the
Radical Reformation even ended up with the name "anabaptist" (re-baptizer) because they insisted that those who had been baptized as infants needed to be baptized again once they were of an age to "choose."
The other view is that baptism is, itself, one of the ways that God uses to work in His people, rather than a symbol that WE do. It is a means of grace, and through it we are adopted into the family of God. Through it the Holy Spirit begins His work in our lives. People who hold this view (by far the oldest view of baptism, and the most widely held) usually baptize their children in obedience to Christ's command. The idea of re-baptizing is not only strange, and seen as redundant, it can also be considered blasphemy, because it may seem like it's saying that God's work was incomplete without some action on the believer's part. Especially for those whose creed includes "Faith Alone", that makes little sense.
In our services, for instance, we pray ".. that You would behold [name] according to your boundless mercy and bless [name] with true faith by the Holy Spirit, and that through this saving flood all sin in him which has been inherited from Adam and which he has committed since, would be drowned and die. Grant that he be kept safe and secure in the holy ark of the Christian Church, being separated from the multitude of unbelievers, and serving Your name at all times with a fervent spirit and a joyful hope, so that, with all believers in Your promise, he would be declared worthy of eternal life; through Jesus Christ our Lord"
I hope that helps clarify why some of us believe infant baptism is just as "valid" as adult baptism, even if the child doesn't know or can't profess her faith.
This really isn't the place for debate, however.
If you want to discuss this specific doctrine, rather than the OP's request for advice, I'd suggest visiting the Sacramental/Ordinance Theology forum. There's always a thread or five on various permutations of adult baptism and infant baptism with lots of Scriptural and historical evidence for both.
I do partly agree with the mormon about the christening not saving you. Although this act alone 'cannot' save anyone, I'd still recommend getting baptised as an adult also. I was christened as a baby, but because of my age it was more a wonderful display of faith on my 'parents' part, not my own. Bapstism in the Bible has to do with a person making a concious, knowing, outward commitment to God in their decision to be baptised. Christening cannot provide this because we are too young to understand what we're doing.
That can be a good trait.
