8 Wherefore, my brethren, since the Lord says briefly, “I am the light of the world: he that follows me shall not walk in darkness, but shall have the light of life;” in these words He has commanded one thing, promised another; let us do what He has commanded, that we may not with shameless face demand what He has promised; that He may not say to us in His judgment, Have you done what I commanded, that you should expect what I promised? What have You commanded, then, O Lord our God?
He says to you, That you should follow me. You have sought counsel of life? Of what life, but of that of which it is said, “With You is the fountain of life”? A certain man heard it said to him, Go, sell all that you have, and give to the poor, and you shall have treasure in heaven; and come, follow me. He followed not, but went away sorrowful; he sought the “good Master,” went to Him as a teacher, and despised His teaching; he went away sorrowful, tied and bound by his lusts; he went away sorrowful, having a great load of avarice on his shoulders.
He toiled and fretted; and yet he thought that He, who was willing to rid him of his load, was not to be followed but forsaken. But after the Lord has, by the gospel, cried aloud, “Come unto me, all you that labor, and are heavy laden, and I will give you rest; take my yoke upon you, and learn of me, for I am meek and lowly in heart,” how many, on hearing the gospel, have done what that rich man, on hearing from His own mouth, did not do? Therefore, let us do it now, let us follow the Lord; let us loose the fetters by which we are hindered from following Him.
And who is sufficient to loose such bonds, unless He help, to whom it is said, “You have burst asunder my bonds”? Of whom another psalm says, “The Lord looses them that are in bonds; the Lord raises up them that are crushed and oppressed.”
Source: Tractates on the Gospel of John (New Advent)