Did you know there is a specific reference in the New Testament that connects the number eight with baptism?
"For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
By which also he went and preached unto the spirits in prison;
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..."
1 Peter 3: 18-21, emphasis added
These eight souls were Noah and his wife, together with Shem, Ham, Japheth and each of their wives. They were saved “by” or “through” the flood water by boarding the ark. I infer also that they all had received baptism, since this law was taught and practiced by righteous followers of God since the days of Adam. (Moses 5: 58-59; 6: 50-68)
The phrase "the like figure" could also be written as "the same number," meaning eight is the number Peter is unmistakably associating with baptism, and with which the readers of Peter's epistle would have been familiar.
Eight days was the appointed age for circumcision, according to that law. (Genesis 17: 12; Luke 2: 21)
What does eight have to do with baptism, and why does Peter mention it?
Answer:
It is the minimum age, in years, prescribed by God as that which should be attained before baptism, when children begin to be accountable before Him. (Doc. & Cov. 18: 42; 20: 71; 29: 47; 68: 27; 137: 10)
See also:
Moroni 8
Doc. & Cov. 74