Jesus is saying that “these things” meaning the mystery of God remains a mystery to the “learned and the clever” but not to “mere children” – to “children” it’s revealed.
Now the first thing I should say is that this is not an argument against learning; it’s about the human heart.
Once again Jesus uses something that we can all understand, in this case a child, and he uses it to teach us about God.
Think of the child-parent relationship. A child spends so much time with his or her parent(s); all day and all night at first, gradually the child is weaned but for years it’ll be there first thing in the morning, many times during the day, then in the evening and last thing at night.
Many of these times correspond to the times when the Church encourages us to pray.
In the child-parent relationship the whole foundation of the child’s future life is laid and as the child matures, provided the child-parent relationship has itself matured, the child will be trusted with virtually everything, even the family secrets! Eventually the child will be trusted with the family business. Remember this is not really about a child-parent relationship but about our relationship with God.
There’s so much in this image of a child; there’s the difference between the child (son or daughter), the servant (employee) and the biblical-historical understanding of a slave, words full of spiritual meaning. It’s the son or the daughter who will inherit, not the employee! The sons place is assured.
And if the child doesn’t want the inheritance or can’t be trusted with it, what’ll happen? It’ll probably be given to someone who can be trusted. Remember the passages where the kingdom is taken from people who fail to produce its fruit and given to others who will produce something?
Only when our relationship with God resembles the very best child-parent relationship will God reveal “these things” to us.
So here in just one image, in that of a child, Jesus teaches us almost everything we need to know about God and our relationship with God.