Matthew 18:3-4
3 And said, Verily I say unto you, Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven.
4 Whosoever therefore shall humble himself as this little child, the same is greatest in the kingdom of heaven
We are supposed to be mature and hold ourself to a high standard. Why would Jesus tell us to be like little children? They lack maturity. They do not know how to accept the harsh reality of life. They do not know how to give up on impossible odds. That is exactly why we need to be like them. They have a faith that we have forgotten. Watch a child pray. It is so heart felt and pure. They put their whole heart into it. Then when they finish they honestly believe it will happen. Unlike us they only look for the good to happen. They look for God to heal sickness when we run for the medicine cabinet. When they hear us complain about money they have so much faith that God will provide, we will start looking for extra shifts at work. This is why Jesus wants us to humble down and be like them. We need to have the faith that our medicine cabinet cannot heal us like God can. Learn the faith that God can make money literally grow on trees. He put money in the fishes mouth. Have the faith once more that the mountains can and will be moved. We need to find our childlike faith again.