I. Consider that a single mote may hinder a man from becoming a true Christian. It is the things which are apparently the smallest that prevent the greatest results. A slight defect in the finest bell and it ceases to sound, a lost key and the richest money-chest is useless. The day of battle has arrived, the troops are admirably disposed, the despatches of the general fly here and there; suddenly the horse of the adjutant stumbles on a stone; he arrives a quarter of an hour too late, and the battle is lost. So it is in spiritual matters. Many a man who has got safely over the Rhine has been drowned in a little brook. Sin has no more dangerous delusion than to convince a man that he is safe if only he avoids the so-called flagrant transgressions. We see this in the case of the young man in the Gospel. He thinks he has kept all the commandments which the Lord names to him. He is evidently a youth of earnest and noble disposition. The question, "What good thing must I do, that I may have eternal life?" was no mere idle phrase, but a question of conscience. Otherwise, how differently our Lord would have regarded him! The very command, "Go and sell that which thou hast," rests on the assumption that he was no mere common miser. Our Lord points out to him that his heart is not yet fixed exclusively on God, that it is still divided between God and the good things of this world. And because of this mote, the door of eternal life, the latch of which is already in his hand, refuses to open.
II. Consider next why this is so. I answer, because if the mote is an unconscious sin, then, as in the case of this youth, repentance is lacking; if a conscious sin, the confidence of faith. Repentance and faith, these are the two parts of conversion, without which no man enters the kingdom of heaven. The young man was grieved. It was merely a mote which the Lord pointed out to him, but to a disposition like his it was enough. In that one evil speck he understands how it is with his heart as a whole.
III. How can this state of things be remedied? First, we must recognize that, if prayer and faith will not open the door, the reason cannot be in the door itself, for over it the words are written, "Come, ye weary and heavy-laden." Some sin must have thrust itself in and hindered our entrance. "Cut it off and cast it from thee." The motes conceal the secret of salvation from your eyes, and you shall find no rest of soul while you seek to serve two masters. Our Lord said, "Sell all that thou hast." And He allows the youth whom He so loved to depart, and we do not learn that he ever returned. We see then how earnest the Lord's meaning was when He said, "Cut it off and cast it from thee."
A. Tholuck, from the Gewissems-Glaubens und Gelegenheits Predigten,p. 193.