To paraphrase Martin Luther; no, Baptism isn't necessary for salvation. It's also not optional. I think that would sum up the way most UMC folks feel about the issue, and is pretty consistent with our views. The UMC doesn't believe that Baptism is a pre-requisite for Salvation in the sense that one is denied grace if they haven't received the Sacrament. Martin Luther did wonder if one could still be saved if they actively refused Baptism, which is an interesting question, but nevertheless. We don't believe one must be Baptized to know grace. However, we also don't believe that Baptism is something that's optional. You can't join a church without being Baptized, and Baptism remains the pre-requisite for all aspects of the life of the church; save for communion. Though our denominations official doctrine of Communion is that Baptism should precede it, we have a very strong conviction that we don't turn people away from the Lord's Table. Simply put, it wasn't out invitation to the table; it was Christ's. And likewise, it's not ours to refuse. But in teaching; we teach that one should first be Baptized, then be connected to other aspects of the life of the Church. For most Methodists, this means being Baptized as children; in the tradition of the Apostles; who Baptized entire families together.
And yep, methodology is the symbolic part. The Baptism is sacramental, it transcends human hands. It's God at work in our lives in a very tangible, incredible way. Over the centuries, Christians have used a great number of methods to Baptize. In the UMC, we recognize and use the three most common throughout history; sprinkling, pouring and immersion. My preference is pouring when practical; I like the abundance of water. Sprinkling works best for infants. I've only done immersion once. That's very regional. Here in mid-Missouri; few folks are that concerned about it. My colleagues in the south often run against it though. Oh, and using the Baptist pastors Baptistry? Psh, I'm from the country... we use the river!
I will say one thing re: methods. Part of a Pastors responsibility is to teach and disseminate theology. I won't ever refuse to Baptize someone because of their choice of Method; but I will sit down with them and have a conversation about why their choosing that. If they chose immersion (or pouring, or sprinkling) because they think that's the only method that 'works', then I'd at least make a plea for a more historically Christian perspective on Baptism rather than a 19th century American Protestant perspective on Baptism. But in the end, I'd still Baptize. Again, God's work, not mine. If we were required to have everything in order and figured out prior to Baptism, nobody save for Christ would've ever been Baptized in earnest.
