Good and blessed is that simplicity which some have by nature, but better is that which has been goaded out of wickedness by hard work. The former is protected from much complexity and the passions, while the latter is the gateway to the greatest humility and meekness. There is not much reward for the one and no end of reward for the other.
If you wish to draw the Lord to you, approach Him as disciples to a master, in all simplicity, openly, honestly, without duplicity, without idle curiosity. He is simple and uncompounded. And He wants the souls that come to Him to be simple and pure. Indeed you will never see simplicity separated from humility. St. John Climacus
Walk before God in simplicity and not with knowledge. Simplicity is accompanied by faith; but subtle and intricate deliberations, by conceit; and conceit is accompanied by separation from God.
St. Isaac the Syrian
When Abba Anthony (the Great) thought about the depth of the judgments of God, he asked, "Lord, how is it that some die when they are young, while others drag on to extreme old age? Why are there those who are poor and those who are rich? Why do wicked men prosper and why are the just in need?" Then he heard a voice answering him, "Anthony, keep your attention on yourself; these things are according to the judgment of God, and it is not to your advantage to know anything about them.”