He is the radiance of the glory of God and the exact imprint of his nature, and he upholds the universe by the word of his power. (Hebrews 1:3)
The true power of the church lies in Christ personally. You may have all the stars that ever made bright the Milky Way with their combined sheen, but there is no power in them to kill evil or conquer sin
The stars of the church shine because God makes them shine. Their shining is not their own: it is a borrowed light with which they are radiant. But the power that overcomes evil, wounds the heart, pierces the conscience, and kills reigning sin is of the Lord alone.
“Out of his mouth went a sharp two-edged sword” (Revelation 1:16). Glory not, therefore, in men; for power belongs unto God. The power lies in Christ’s Word. “Out of his mouth went a sharp two-edged sword.”
“He that hath my word, let him speak my word faithfully…saith the LORD” (Jeremiah 23:28). People are disturbed and troubled by the real gospel: under the false gospel they can sleep unto destruction. Bring out the sword: it is made to wound; let it exercise its salutary sharpness.
The gospel has two edges so that none may play with it. When they think to run their fingers along the back of it, they will find themselves cut to the bone. Whether we regard its threats or its promises, it cuts at sin.
Let us therefore know that the power of the church does not lie anywhere but in the Word as Jesus himself speaks it. Let us keep to his own pure, unadulterated, unblunted Word, and let us pray him to send it forth with power out of his own mouth into the hearts and consciences of men.1
 Charles Spurgeon, At the Master’s Feet [Grand Rapids: Zondervan, 2005], January 27.
Hat tip to http://apprising.org/