This comes from a longer address at a student missionary convention held in Cleveland, Ohio. You can read the rest of the address at this link:
I remember so well, dear friends, the day when Charley Studd looked into my face and said, "Mr. Meyer, there is nothing I have got that you may not have"; he looked so bright. I can see him now that autumn morning, standing there in his cricket flannels. It was rather chilly and the morning sun was streaming in the uncurtained window and the candles were burning low on each side of his open Bible. And I said to him: "You have been up early." "Yes," said he, "I got up at four o'clock this morning. Christ always knows when I have had sleep enough, and He wakes me to have a good time with Him." And I said: "What have you been doing this morning?" And he said: "You know the Lord says, 'If ye love Me, keep My commandments,' and I was just looking through all the commandments that I could find that the Lord gave and putting a tick against them if I had kept them, because I do love Him." "Well," I said to him, "how can I be like you?" He said: "Have you ever given yourself to Christ, for Christ to fill you?" "Well," I said, "I have done so in a general way, but I don't know that I have done so particularly." He said: "You must do it particularly also." I knelt down that night and thought I could give myself to Christ as easily as possible. And I gave Him an iron ring, the iron ring of my will, with all the keys of my life on it, except one little key that I kept back. And He said: "Are they all here?" I said: "They are all there but one, the key of a tiny closet in my heart of which I must keep control." He said: "If you don't trust Me in all, you don't trust Me at all." I tried to make terms; I said: "Lord, I will be so devoted in everything else, but I can't live without the contents of that closet." I believe, young friends, that my whole life was just hovering on the balance, and, if I had kept the key of that closet and had mistrusted Christ, He never would have trusted me with His blessed Word. He seemed to be receding from me, and I called Him back and said: "I am not willing, but I am willing to be made willing." It seemed as though He took that key out of my hand and went straight for that closet. I knew what He would find there, and He knew, too. Within a week from that time He had cleared it right out. But He filled it with something so much better! Why, what a fool I was! He wanted to take away the sham jewels to give me the real ones. He just took away the thing which was eating out my life and instead gave me Himself.
Now, that is the point I am coming to with you. You have given Him the keys, haven't you? You have given Him your will with every key of your heart and life. It is all in His hands. If He would send you to India, you would go. If He would send you to Japan, you would go. If He would ask you to give up the dearest idol that your heart knows, you have given it up. So far as you know, you just want to be the slave of Jesus. I believe if I should ask you, you would be willing to go anywhere and do anything for Jesus, to make any sacrifice He asked, though it was to lay down your life in a tropical land in a fever-stricken latitude; I believe if I should ask you I should have every man or woman in this house on his or her feet. Oh, I believe Jesus must be looking down on you and feeling that it is worth having died for. I believe He says to Himself: "Well, the thorns were sharp and the nails were bitter and death was terrible, but it is worth it all to have the love of these young men and women." I believe He is repaid. Have you left a little ingredient of bitterness in His cup, because you are not with us? Come along, join in, step up now, come, and don't let there be one jarring note in this great orchestra to-day, but let every one of you be sweetly attuned to Jesus in entire surrender. I have it! I hear from hundreds of hearts the cry, the murmur, "All for Christ." Yes, yes, remember, if you are all for Christ, Christ is all for you. That is it. That is the blessedness of it. And I must give you a text to remember, because it is better to have His word than mine: Colossians i. 19. "It pleased the Father that in Him should all fullness dwell." And in Colossians ii. 9, 10, "For in Him dwelleth all the fullness of the Godhead bodily. And ye are complete in Him"—ye are made full, ye are complete in Him.—Taken from an address given at a student convention that was held in Cleveland, Ohio February 23-27, 1898, and recorded in the The Student Missionary Appeal, Addresses at the Third International Convention of the Student Volunteer Movement for Foreign Missions, pp. 3-17