One thing thou lackest.
I. This young man, immortalised in the everlasting word, was not a phenomenon, he was a type. We see him so distinctly in his own question, "What shall I do that I may inherit eternal life?" Yes, here is enquiry, anxiety therefore, desire to be right, admission that there may be a higher height, a loftier attainment, than the life has yet reached; respect too, and reverence for one who is neither priest nor Rabbi nor ruler, who has neither rank, nor office, nor philosophy, nor oratory, but only the two things, sincerity and sanctity, to recommend him. This there is in the young man, and it brings him where all are welcome who would know and do; brings him running, brings him worshipping, and sets him face to face with Jesus Christ. Besides the spirit of enquiry and the spirit of reverence, there was a third thing in that character; a memory of morality, a habit of virtue. At the very moment that he is asking, What shall I do? his heart is saying within him, What lack I yet? He thinks, perhaps, when he asks that question, of some little finishing stroke, some last ornament and embellishment of perfectness, which may cost him an effort, but which at least need not undo nor unmake anything.
II. When Christ says to this moral young man, "Yet lackest thou one thing," we understand Him to say, "And that one thing is needful." He who puts it away from him, as either unnecessary for him or unattainable, counts himself unworthy of everlasting life. That which was lacking in the young man was, in one word, devotion; not devotion in the sense of devoutness, but devotion in the sense of self-surrender. The love of Christ stops not with gilding or refurbishing men, it sets open eternity. One thing thou lackest thy soul must be athirst till she has it union with the alone good One, the having Him in thee, the being at one with Him now and world without end. To have this thou must part with all else: in act, if Christ bids thee; in will, at all events, because Christ calls thee. The young ruler went away sorrowful. The love of Jesus was wasted upon him for this time, and the Gospels which tell of the going tell of no return. The moral, at all events, is thus written. It is not the second chance, it is not the late hope, it is not the last first, which is here recorded for our learning; it is the peril of refusing Christ's call, of saying to Him, "I will not," when He bids us follow, of preferring earth when He offers heaven.
C. J. Vaughan, University Sermons,p. 354.
I. The one thing which Christ sees wanting in so many of us is expressed clearly in the latter part of His words to the young man in the Gospel. He tells us, "Come, take up the cross, and follow Me." The words are figurative, we see, when He says, Take up the cross, and we may ask what the figure means. But we know that in the Latin language, the term cruxor cross had been long used to express generally any great pain or evil; and the words crucioand cruciatusderived from it are yet used only generally; they do not express literally the pain or suffering of crucifixion, but pain and torment simply. And this manner of speaking has come into use, because the Romans used the punishment of crucifixion commonly, not only towards slaves, but towards criminals generally of the subject nations, unless they were persons of high condition. So that when our Lord tells the young man to take up his cross, it means exactly, "Bear thy pain or thy suffering, whatever it may be, and follow Me."
II. Christ calls us to take up our cross and follow Him. We were following Him, not taking up our cross; we were following Him where to follow Him was easy, and it is many times very easy. Do not go away grieving, when you hear Christ's call, because you are young, and faithful steady service of Christ will cost you many a sacrifice. Turn not from Him, but to Him much rather, with earnest prayer that He who bore His most painful cross for you, will enable you to bear your light one for His love; that He will help you daily, as your trial will come daily; that His strength may be made perfect in your weakness. And then, though the thing be harder than that a camel should pass through a needle's eye, yet it shall be done. The young, with all their carelessness, with all their difficulties from without as well as from within, shall enter into the kingdom of God; for so some have entered, and so shall some enter again, and so may all enter who do not turn away from the cross, but ask Christ's grace to help them to bear it.
T. Arnold, Sermons,vol. v., p. 246.
References: Mark 10:21; Mark 10:22. Preacher's Monthly,vol. iv., p. 50; R. Duckworth, Christian World Pulpit,vol. xxii., p. 168. Mark 10:23 G. Huntington, Sermons for Holy Seasons,1st series, p. 237.