There is a subtle difference between being childlike and being childish. In today's Gospel we hear that the hidden treasures of the Gospel are revealed to the childlike and not to the "wise and the learned" whom we might expect to be likely candidates for such knowledge.
What is it that makes one childlike as opposed to childish? One very simple, approach might be to sift through the characteristics of children and separate the endearing qualities of a child (which many of us adults would do well to cultivate) from those which are unbecoming of grown-up members of our species. To name a few, we might list selfishness as a characteristic of one who is childish and curious as a quality of a child. Think how often children ask "Why? or How?" We might do well to ask some of these questions in our hearts as we ponder the immensity of the Lord's love for us. We could speculate that one who is childish lacks direction in his life and one who is childlike is "coachable" and takes direction easily and willingly. How easily and how gratefully a child will follow the encouragement of an adult whom he loves and respects. How much more readily ought we to follow the gentle tug of the Lord as He calls us -- each day -- to align our lives with His will for us.
St. Francis de Sales had a few suggestions of his own as to how we might imitate the more positive qualities of a child. This excerpt is from his "Treatise on the Love of God."
"Imitate a little child, whom one sees holding tight with one hand to its father, while with the other it gathers strawberries or blackberries from the wayside hedge. Even so, while you gather and use this world’s goods with one hand, always let the other be fast in your Heavenly Father’s Hand, and look round from time to time to make sure that He is satisfied with what you are doing, at home or abroad. Beware of letting go, under the idea of making or receiving more—if He forsakes you, you will fall to the ground at the first step. When your ordinary work or business is not specially engrossing, let your heart be fixed more on God than on it; and if the work be such as to require your undivided attention, then pause from time to time and look to God."
St. Francis de Sales