How was Baptism prefigured in the Old Testament?

Answer 1

Peter points out that the flood was a "type" (prefigure) for baptism in 1 Peter 3:20, 21:

who formerly were disobedient, when once the Divine longsuffering waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight souls, were saved through water. There is also an antitype which now saves us-baptism (not the removal of the filth of the flesh, but the answer of a good conscience toward God), through the resurrection of Jesus Christ, [NKJV]

The passage of the Israelites from Egyptian bondage (compare to "slaves of sin" - Romans 6:6 and 17) through the Red Sea also prefigured baptism.

Answer 2

The only even that comes to mind that could be representative of baptism in the Old Testament is what is referred to as Noah's Flood, many scholars and historians believe that this "flood" was depicting the need for "man's" salvation and the "cleansing" of their sins.

It wasn't until the birth and death of Jesus. Before the Crucifixion, there was no need for baptism. The atonement for man's sin was in the form of a sacrifice made by the High Priest, up until after the Crucifixion, man could not atone for his own sins.

Jesus Christ being the ultimate "sacrifice" died for all of the worlds sin, the curtain in the temple was torn as a representation that Man could now atone for his own sins through prayer, salvation, and baptism, the cleansing of the soul through water in the name of Christ.