The Bible explicitly makes a distinction between Baptism in the Spirit and water baptism. We see this in the case of Cornelius of Acts 10 in which he received the Spirit before being baptized. In Acts 11 Peter explains such a receiving of the Spirit as the Baptism with the Holy Spirit. (Acts 11:16) Therefore when the Bible makes reference to "baptism", we have to consider which baptism it is referring to. Furthermore, the word "baptism" simply means to immerse one thing into another. Water may have nothing to do with it.

Rom 6:2-4
By no means! We died to sin; how can we live in it any longer? Or don't you know that all of us who were baptized into Christ Jesus were baptized into his death? We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life.

* No mention of baptism into water here! Instead of being baptized into water, these are baptized into his death.

Gal 3:27
 for all of you who were baptized into Christ have clothed yourselves with Christ.

* No mention of water here. These are baptized into Christ, not into water.

Col 2:11-12
In him you were also circumcised, in the putting off of the sinful nature, not with a circumcision done by the hands of men but with the circumcision done by Christ,  having been buried with him in baptism and raised with him through your faith in the power of God, who raised him from the dead.

* This certainly can't refer to water baptism as that is done in the flesh by hands, much as circumcision is. Again this refers to baptism into his death.

1Peter 3:20-21 (kjv)
Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water. The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ:

* Here the like figure is the story of Noah in which he was placed into the Ark and God shut the door. The ark represents Christ and the water represents God's wrath. It was not Noah that got wet, but rather those who perished. So here water is not associated with salvation, but with condemnation. The "by water" is really "in the midst of the waters" as in "through the waters". The KJV and NIV have translation errors in these verse. Waters is not a mechanism of salvation in the story of Noah, the ark is. Furthermore Peter makes clear that he is not talking about getting wet ("putting away the filth of the flesh"), but rather repenting and turning to Christ.

Mark 16:16
Whoever believes and is baptized will be saved, but whoever does not believe will be condemned.

* This is referring to water baptism. But it doesn't say that he who believes but has not been baptized will be condemned. It only deals with the case with those who believe and are baptized and with the case of those who don't believe. But there are plenty of verses that make reference only to faith in Christ for salvation, such as John 3:16.

Acts 22:16
And now what are you waiting for? Get up, be baptized and wash your sins away, calling on his name.'