And no man putteth new wine into old bottles: else the new wine doth burst the bottles, and the wine is spilled, and the bottles will be marred: but new wine must be put into new bottles. Mark 2:22.
We need to be constantly filling the mind with Christ, and emptying it of selfishness and sin. When Christ came into the world, the leaders of the Jews were so permeated with Pharisee-ism that they could not receive His teachings. Jesus compared them to the shriveled wineskins which were not fit to receive the new wine from the vintage. He had to find new bottles into which to put the new wine of His kingdom. This was why He turned away from the Pharisees, and chose the lowly fishermen of Galilee.
Jesus was the greatest teacher the world ever knew, and He chose men whom He could educate, and who would take the words from His lips, and send them down along the line to our time. So, by His Spirit and His Word, He would educate you for His work. Just as surely as you empty your mind of vanity and frivolity, the vacuum will be supplied with that which God is waiting to give you—His Holy Spirit. Then out of the good treasure of the heart you will bring forth good things, rich gems of thought, and others will catch the words, and will begin to glorify God. Then you will not have the mind centered upon self. You will not be making a show of self; you will not be acting self; but your thoughts and affections will dwell upon Christ, and you will reflect upon others that which has shone upon you from the Sun of righteousness.
Christ has said: “If any man thirst, let him come unto me, and drink” (John 7:37). Have you exhausted the fountain?—No; for it is inexhaustible. Just as soon as you feel your need, you may drink, and drink again. The fountain is always full. And when you have once drunk of that fountain, you will not be seeking to quench your thirst from the broken cisterns of this world; you will not be studying how you can find the most pleasure, amusement, fun, and frolic. No; because you have been drinking from the stream which makes glad the city of God. Then your joy will be full; for Christ will be in you, the hope of glory.