An engraving was made in the baptismal dish. An octagon is visible in the center. Lines run from the bottom to the top edge of the bowl, four times three lines, symbolic of God’s Triune and the cross. The circular bowl shape indicates the God Who is eternal. After all, a circle has no beginning and no end....
The octagon has its origins in the early church (2nd and 3rd centuries A.D.). The number eight refers to the eighth day on which the circumcision of Jesus took place. It also refers to Noah, his eight souls were preserved and kept which indicated baptism. In the New Covenant, no longer the seventh day (Sabbath), but the eighth day (Sunday) is the Lord's Day, since that was the day of Christ's resurrection from the dead.
Thus baptism is also the beginning of a new life and an resurrection from spiritual death, and refers to the joy of Christ's resurrection and eternal life.
And finally, the eighth day is the day still to come. Creation lasted seven days. The time that will come to pass is 'the eighth day': a time of consummation, in which creation will be redeemed. Thus eight is the number of a new beginning, of re-creation.