If you are teaching the Lord’s Prayer and are asked what forever and ever means, then it means something like the sequence of numbers or days from the Peano Axioms.
The phrase “without end” also has a similar meaning.
The Peano Axioms codifies what a sequence without end means. It starts at a unique point, and then has a sequence of links, with each link having a single following link, and all links but the first a single predecessor link.
The Peano Axioms reinforce teaching the Lord’s Prayer because they help create meaning for the phrase “forever and ever”. They also help teach the concept of links or connections.
A link is an ordered pair (n,n’) where n’ means the one after n. This is before addition is defined. The meaning of n’ is a direct following of n. (Monday, Tuesday). We do not need to define addition of days to have Tuesday follow Monday.
By learning some math and logic that goes with the phrases or sentences of the Lord’s Prayer it helps make it more meaningful. It also is a base to understand the further theology of the Lord’s Prayer. It helps connect the phrases together, make them meaningful, and make them easier to remember.
The Peano Axioms can be taught along with the Lord’s Prayer for first graders to learn. They will make it seem more relevant and to have a deeper meaning.