There is no concept harder to explain to a toddler, a youth, or even an adult than the Trinity. We explained to my three year old Connar the other day that Jesus lives in heaven, but now He doesn’t believe that Jesus lives in Florida. That’s a fun one.
The ontological, or essential unity and yet distinction within the Trinity is described in by the Westminster Shorter Catechism Q. 6
WSC Q 6: How many persons are there in the Godhead? There are three persons in the Godhead. The Father, the Son, and the Holy Ghost. But these three are one God, the same in substance, equal in power and in glory.
You can actually hear it sung by an accomplished musician here. In fact I just used this music to verify the correct wording now that my bibleworks program doesn’t work any longer with my new Apple operating system.
There really isn’t an illustration or example that is technically accurate when describing the essential unity and yet distinction in the Trinity. Pretty much all of the examples teachers tend to use (and not deviously mind you) are actually heretical forms of what is called “modalism” or Sabellianism (where God appears at one time Son, another time Spirit, another time Father but not all at once). And so we’re kind of limited to holding tight to the scriptures, and to the language passed down to us from church history.
However, I don’t think we’re necessarily limited on illustrations describing the functional subordination (where each member honors and points to the next person) relationship within the Trinity. What I mean is that the Spirit points to the Son, the Son points to the Father, the Father points to the Son. A little bit of that can be seen in John 16:12-15.
We’ve been trying to get my one year old son Cade to talk, but he’s only got the “da-da” sound down. He can probably say that word because my wife Amy, who obviously spends the most time with him, always pointed him toward “Da-da.” She is incredibly important in Cade’s life, but she wanted to point him toward someone else equally as important. When I’m with Cade, I try to get him to say “Ma-ma.” I also try to get Cade to say Connar’s name “Ca-ca” (he did ONCE and that was it.) I don’t need to hear him say my name; I desire him to say the names of his mother and brother. I want to honor them. And they want to honor me. Neither of us is essentially more important (though you could obviously argue she gets the nod from me), but we each sense the need to bring honor to the other.
Maybe this helps. Maybe it doesn’t. Like any analogy it has limits, but it makes sense to me.