When we'd get back into the vehicle after a stop, she'd settle into her booster seat and call to us from the back, "Tell me all about ..." and she'd name a topic.

Birds. Rain. Ears. Watermelons. Toilets. Football.

You name it, she wanted to know about it, with seemingly no rhyme or reason to the topics she'd list off.

We'd do our best to muddle through some basic information, my science teacher husband far better than me at answering questions about bugs or weather or the human body.

Finally, on the long drive back to Louisiana after two weeks away from home, Rose excitedly said from the back: "Tell me all about Jesus."

This was my moment, theology teacher Katie of the old days ready to whip out my old tricks.

"Jesus is the second person of the Trinity, the son of God, Word made flesh dwelling among us, who died for our sins. And he loves you very much!"

"But why?"

Ah, the million dollar question that usually followed as soon as we'd introduce any topic.

But I was ready.

"Jesus loves you because you are made in his image and likeness, and worthy of his love."

"Oh."

The questions quickly stopped. Unlike her -- she would usually pepper us for a solid 10 minutes as we'd dig into a topic.

"Any more questions?" I excitedly asked Rose.

"No."

Confused why she suddenly lost interest, I tried again.

"Are you sure? I could tell you a lot more."

"Well normally you and Daddy have to go look things up on your phone before you answer my questions, but this time you just knew it all already. I guess I like it best when we learn about stuff together. But you know it all, so I'm the only one that has to learn this time."

My husband and I looked at each other stunned. Kids have an amazing way of saying things you perhaps didn't even realize they were mature enough to really think about.

"Oh, baby, I promise I don't know everything about Jesus. I have a lot to learn too!"

"But you do! You do know everything about Jesus!"

I sighed deeply.

"No, baby. I will never know everything about Jesus, and neither will you. And that's really kind of the best. All we can ever really do is just try to know him a little bit more every day."

"Nice save," my husband whispered from the driver's seat.

"Oh. OK. Did Jesus ever have tummy aches and what do you think he ate for breakfast?"

And we were right back to it, this time with questions about Jesus I did need to think about.

The precocious questioning of a curious 4-year-old has taught me plenty about random subjects, but also reminded me of the most necessary thing to cling to, perhaps especially in moments when faith becomes a challenge to live, church teaching becomes confusing to understand and share, or when Jesus feels distant and hard to feel.

We will never know it all. When it comes to Jesus, there are infinite amounts to learn. We will never be done learning about him, the alpha and the omega, who is truth itself, made present to us, died for us and loves us.

And we will never be done simply learning who he is -- learning how he loves us, and why, and coming to experience his presence in new ways each day.

Honestly, I'd be happy to answer questions about that from anyone, but especially my daughter, all day.

Katie Prejean McGrady is an award-winning author and host of The Katie McGrady Show on Sirius XM's The Catholic Channel. She lives in Lake Charles, Louisiana, with her husband and daughters.