One the questions I am most often asked by evangelicals is whether or not a child who is baptized is "saved". I always answer in the affirmative, of course, but then go on to mention how the scriptures speak of us as saved, being saved, and that we will be (or hope to be) saved. Then we usually get into a discussion of salvation is more of a process, with baptism as the beginning of it, rather than a one-time event that is followed by sanctification. And then, of course, a million other related issues come up. These are always very interesting discussions, and we always go away from them with much to think about.
I have never been able to figure out why some Christians object to baptismal regeneration. Usually they have two objections. First, they seem to think it is "too much grace"; God is nice, and good... but not that nice and good. God is powerful, and can perform great and marvelous acts, but He would never use water and some words to effect a change in a person's heart! It is amazing how we limit God. Why would God not use physical things to save us? Oh, wait a minute, He did - His only begotton Son dying on a cross... that was physical. So, this objection is usually pretty easily dealt with based on simple reasoning alone, and when it is coupled with scriptural and patristic evidence people usually become more open to it.
Second, many people get completely distracted by this business of "making a personal decision for Jesus." How can an infant chose to "accept" Jesus? Faith and repentence are necessary for baptism, but in infant baptism in the catholic tradition godparents (or parents) make those vows on behalf of the child. Later in confirmation, faith is confirmed, as the child ratifies the promises made in his name and vows to follow Christ as his Lord and Savior. I like to think of it in terms of money, or a trust fund. Imagine that you have a little baby, and Bill Gates comes to you and says he wants to give the baby a million dollars, but the child has to accept the gift - meaning, understand the need of money, the value of the gift, and so on. What parent would not want his child to have that gift? None. Rather, he would say to Bill Gates, "I am speaking on behalf of my child... YES, he wants and needs that gift. Give it to him, and I will oversee it on his behalf. When he comes of age he can do with it as he pleases, but if I train him right I am sure he will be a good steward of that gift." So Gates gives him the gift, and it is a real gift that is truly the baby's. I am sure that this happens in real life all the time (maybe not with Bill Gates and a complete stranger, but certainly with trust funds, and so on). So why is it so impossible for some to imagine in the spiritual realm?