Mark 10:14-15 Let the children come to me; do not hinder them, for to such belongs the kingdom of God. Truly, I say to you, whoever does not receive the kingdom of God like a child shall not enter it"
When i was around 7 years of age, my younger sister and i used to pray for the restoration of electric power supply. We got answers. In fact, whenever there's power outage and our big sisters and brothers are in desperate need of electric power, they'll call on me and my younger sister to pray. We were young and our minds were devoid of impossibilities. We didn't know that certain factors led to power outage, all we wanted was power supply so that we can watch television.
That's the mind of a child. Today, i doubt if i can still pray about the same issue with that mindset that knows no impossibility. Why? Now i know there's something called power generation, transmission and distribution. So in my mind, i'll try to find out what the problem could be and how it maybe impossible to get the power restored on time. When Jesus advocated for Child-likeness in kingdom matters, he knew perfectly that the innocence and child-like heart is the best way to relate with God.
We can get to a point in our walk with God where it may be hard to believe God for miracles. This is very common to those that have been in church for years. You'll see new converts obey every instruction and they'll go home with answers but oldies analyse everything. Sometimes, the worst set of people to preach to and get them have faith for miracles are preachers and theologians. They may be looking for exegetical and homiletical loopholes in your message and thereby losing out. Children trust their parents for everything and they demand for costly things ignorantly. Their believe is that daddy is so rich and can buy anything for them. When will you start trusting God like that?
Switch on that child-like faith in you and ask for whatever you want from God without doubting in your heart. Mark11:23-24.