One of my favorite Spurgeon quotes:
“A church…which does not exist to do good in the slums, and dens, and kennels of the city, is a church that has no reason to justify its longer existing. A church that does not exist to reclaim heathenism, to fight with evil, to destroy error, to put down falsehood, a church that does not exist to take the side of the poor, to denounce injustice and to hold up righteousness, is a church that has no right to be. . .
Church of God, your mission is not to the respectable few who will gather about your ministers to listen respectfully to their words! Your mission is not to the elite and the eclectic, the intelligent who will criticize your words and pass judgment upon every syllable of your teaching! Your mission is not to those who treat you kindly, generously, affectionately!
Not to these, I mean, alone, though certainly to these as among the rest. But your great errand is to the harlot, to the thief, to the swearer and the drunkard, to the most depraved and debauched! If no one else cares for these, the Church always must, and if there are any who are first in her prayers it should be these who, alas, are generally last in our thoughts. The ignorant we ought diligently to consider. It is not enough for the preacher that he preaches so that those instructed from their youth up can understand him. He must think of those to whom the most common phrases of theological truth are as meaningless as the jargon of an unknown tongue. He must preach so as to reach the meanest comprehension, and if the ignorant many come not to hear him, he must use such means as best he may to induce them,no, compel them to hear the Good News.”
C.H. Spurgeon (from his sermon “Christ’s Words from the Cross”)