Spurgeon wrote a short sermon on 1 Peter 2:7: “For you who believe, he is precious.” Here is his conclusion:
Every Christian here is either a missionary or an impostor. Recollect that. You either try to spread abroad the kingdom of Christ, or else you do not love him at all. It cannot be that there is a high appreciation of Jesus and a totally silent tongue about him. Of course I do not mean by that, that those who use the pen are silent: they are not. And those who help others to use the tongue, or spread that which others have written, are doing their part well. But that man who says, “I believe in Jesus,” but does not think enough of Jesus ever to tell another about him, by mouth, or pen, or tract, is an impostor. … Be wise in your generation, and speak of him in fitting ways and at fitting times, and so in every place proclaim the fact that Jesus is most precious to your soul.
—C.H. Spurgeon, “A Sermon and a Reminiscence,” from the Sword and Trowel, March 1873, www.spurgeon.org/s_and_t/srmn1873.php.