“I have many things to say unto you, but ye cannot bear them now.” -John 16:12

Now, had certain reputedly wise men been there they would have said, “Lord, let us hear it all; make full proof of it all; bring it all out: we can hear it-only try us.” But our Lord knew what was in man, and, therefore, He only little by little, line upon line, precept upon precept, brought out the truth, and He does so experimentally with His children still. We do not know our own depraved hearts so well at first as we do afterwards. The disease and the remedy have both of them to be more fully revealed to us by-and-by. Did we know at the first all we shall know hereafter, we should be so overwhelmed with the abundance of the revelation that we should not be able to endure it; the Lord, therefore, lets in the light by degrees…If you have been long in the dark, and come into the light at once, your eyes smart, and you cannot bear it, you need to come to it by degrees, and thus is it with the Lord’s children. By little and by little He introduces them into the glory of His kingdom, preparing them for its fullness as children are prepared for their manhood. Have you not seen how the nurse will tempt the child to take a little longer walk, by holding out a pleasant thing to allure it? And how often has our blessed Lord tempted us to some bolder deed of service, to something that required more faith than we had before, by giving us choice signs of His presence, and ravishing our hearts with His love. Some of us know what it is to have seen such sweet results from our little faith, that we could not but desire to try what stronger faith would do. God so rewarded the weak faith we had, that we felt we must rely upon Him, and venture still further. Kindly hath the Lord conducted us onward in this respect.~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1021.cfm