Luther on Immersion?

Luther said, “Even so it is not baptism that justifies or benefits anyone, but it is faith in the word of promise, to which baptism is added. This faith justifies, and fulfils that which baptism signifies.” (“THE BABYLONIAN CAPTIVITY OF CHURCH”) 

The second part of baptism is the sign, or sacrament, which is that immersion into water from this also it derives its name. For the Greek baptizo means “I immerse,” and baptisma means “immersion.” For, as has been said, signs are added to the divine promises to represent that which the words signify, or, as they now say, that which the sacrament “effectively signifies.” We shall see how much of truth there is in this… It is indeed correct to say that baptism washes sins away, but that expression is too weak and mild to bring out the full significance of baptism, which is rather a symbol of death and resurrection. For this reason I would have the candidates for baptism completely immersed in the water, as the word says and as the sacrament signifies. Not that I deem this necessary, but it would be well to give to so perfect and complete a thing a perfect and complete sign. Thus it was also doubtless instituted by Christ. The sinner does not so much need to be washed as he needs to die, in order to be wholly renewed and made another creature, and to be conformed to the death and resurrection of Christ, with Whom, through baptism, he dies and rises again.