This passage is part of the answer to those critics who claim that religion causes hostility and aggression. While it is true that religion is often used as an excuse for aggressive behaviour, the Prophet Zechariah makes clear that the true mark of religious leadership is a resolute determination to see peace prevail. Not only does the true leader choose to ride on a humble beast of burden, but he also cuts off the chariot and the bow, and positively commands peace. He may choose humble symbols like the donkey, but his aim is a worldwide dominion of peace. In other words, true religion is - by definition - almost aggressively peaceful.
The great difference between Christianity and its sister religions, Judaism and Islam, is that while Christianity recognises that holy laws are good in principle, it also recognises that human beings cannot rise to the challenge of being holy - at least not without divine help. There is something about human nature which makes us incapable of doing good even when we know what is right and we want to do it. And, of course, sometimes we don't know what is right anyway, or we believe we are doing right when we are actually doing wrong. It's also possible to have the best of motives and the worst of outcomes.
It is Jesus who rescues us from this predicament. His death shows us that God loves us and is ready to forgive us despite our weakness. But Jesus' death is more significant even than that. Paul explains in his letter to the Church at Rome how we can identify ourselves completely with Jesus' death by crucifying our self-centered self with him and making ourselves his slaves, instead of slaves of human nature, rising to new life in him.
Matthew 11.16-19, 25-30
Religious people may not be responsible for all the hostility in the world, but they can be contrary and hard to please. One vicar, or minister, is criticised for preaching badly even though he's a tireless visitor, with an exemplary pastoral ministry. The next vicar or minister is criticised for spending too little time visiting even though she spends many hours crafting wonderful sermons. Even Jesus encountered exactly the same problem.
If only religious people would relax into the sort of childlike attitude that Jesus describes in his prayer. If we adopted his gentleness and humility we could find rest in him and let go of our constant striving to outdo other people and our critical and fault finding attitudes.