there are two baptisms in scripture, of water and spirit, as John the baptizer pointed out.
but there is one baptism, as the scriptures say.
is it water or spirit?
i have a friend, Joe, who was washed ashore on a deserted island, with food and supplies to live, and with a bible.
can Joe, a sinner never knowing God, be saved? is the scripture, time & health to read it, and a God who sees everyone enough?
i believe if Joe needs to be baptized with water, God Himself can do so with rain or the sea, without anyone to administer his rites or hold his head, and without apologizing to those he'd sinned against in person or evangelizing to another living soul. my God is strong to save.
should we be baptized with water? yes, the apostles practiced it, and in the historical context it was a public display of discipleship. which is what the 'great commission' was - to initiate, train and 'make' disciples. not "fans" or "followers." if for no other reason, we ought to be baptized publicly to avoid being a stumbling block!