Dear Pastor Andy, can you re-baptize a child in another denomination or faith system?
My Reply: I suppose you could re-baptize them, but neither do you need to, nor is it suggested that you do. Biblically and Theologically-speaking, you only need to be baptized once: “One Lord, one faith, one baptism, one God and Father of all, who is above all and through all and in all. (Ephesians 4:5-6).
The short answer to your question is, if they were baptized once, then there is no need to baptize them again.
The problem though is that so many people just do not understand what Baptism is all about. Does it bring salvation or not? Is it inward, outward, or both? If baptism is only about cleansing of sins, the why was Jesus baptized? Should there be age limits? Is baptism communal or individual? How should it be done and what biblical references support the different ways? Is baptism only a Christian-thing?…To help wrestle through some of these questions, I have published several posts on Baptism. I encourage you to search through my blog, or even better yet, my free ministry resources site.