"It {Baptism by immersion}is more than strongly recommended. It is commanded by Jesus personally, and also by His Apostles."
Jesus also commands us to eat His body and drink His blood, or "you shall not have eternal life within you". Not to open another subject, (Eucharist) but why do you follow one teaching to the letter with no room for any other interpretation, and not the other?
Regards
Obviously, in that instance he was speaking symbolically. When Christ spoke of baptism, He was actually getting baptized, so it is kind of hard to conclude he was speaking symbolically there.
Why even argue the point? If you are aware that you should be baptized but you do not, I am sure that will not score you many brownie points. People who are not aware or did not have the opportunity, will be judged on those facts.