In 1 Peter 3:20 it reads: 20 Which sometime were disobedient, when once the long suffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.
Do the 8 souls saved by water have any connection to the age of accountability? I’m just curious, I suppose I do not want to read further into something than there actually is.
The next verse reads:
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:
I have heard some Latter-day Saints interpret the phrase “the like figure” as a reference to the number 8 from the previous verse. After all “figure” is another word for numeral or numeric amount. I find this particular reasoning rather dubious when reading the the two verses together.
Eight souls were saved by water; The like figure … even baptism doth also now save us.
The like figure is actually explained to be baptism. But what is it like? Well, baptism saves us so what saved them? Was it the number of souls or was it the water? It was the water! Read it backwards and see if the likeness still stands.
Baptism doth now save us; the like figure, even water hath also saved them.
This makes a lot more sense than “even eight souls hath also saved them”.
Having said that, we are not surprised to find that there were eight souls saved in the earth’s baptism. Oftentimes numbers are used as symbols and 8 is associated with the related themes of baptism, rebirth, and resurrection. Peter uses that number again when talking about the flood. “[God] saved not the old world, but saved Noah the eighth person” (2 Peter 2:5). It is quite natural then (though not necessary theologically) to find the age of accountability is 8 years old (D&C 68:27). E.W. Bullinger (who often took symbolic numbers to an extreme, but I think this example is valid) sees the theme play out even in the age of circumcision.
Hence, too, circumcision was to be performed on the eighth day (Gen 17:12), because it was the foreshadowing of the true circumcision of the heart, that which was to be “made without hands,” even “the putting off of the body of the sins of the flesh by the circumcision of Christ” (Col 2:11). This is connected with the new creation. (Number in Scripture, part II, Eight by Itself)
Joseph Smith explicitly tied the 8 of the circumcision with the 8 of the baptism in his inspired translation of Genesis (although he doesn’t directly tie it in with the rebirth theme as Bullinger does).
I will establish a covenant of circumcision with thee, and it shall be my covenant between me and thee, and thy seed after thee, in their generations; that thou mayest know forever that children are not accountable before me until they are eight years old (JST Genesis 17:11).
The number 8 appears repeatedly in these themes. In this particular verse you mention I think the central symbol is the water, just as it is with our own baptisms today.