A couple of days ago, my former coach, sometimes-pastor, and potential father-in-law (*crosses fingers*) did a Bible study on Titus 1:1-5. You can read those verses here, and you should, because I'm going to be talking about them. Paul begins by announcing who he is--both a servant of God and an apostle of Jesus Christ. He is both of these things "for the sake of the faith of God's elect"--that is, so that their faith will be maintained and strengthened. Paul says that he is a servant and apostle, working for the sake of God's people, "in hope of eternal life, which God, who never lies, promised before the ages began." His hope and surety of eternal life is rooted in God's eternal promise, given "before the ages began."
All of this is evident and clear from the text, but now we're going to get a little deeper. Just bear with me. Paul, still speaking of this hope and promise of eternal life, says that God manifested this promise "in his word, through the preaching with which I have been entrusted by the command of God our Savior." At first glance, Paul may merely be saying that the promise of eternal life is revealed through his (Paul's) preaching. However, a closer read reveals a deeper, way cooler meaning. A glance at another Bible passage--John 1-- gives us a different understanding of "word" than a simple utterance or saying. According to John, the word of God is, in fact, Jesus Christ. If we keep this in mind when we read Titus, we see that God's promise of eternal life, made before the ages began, is manifested not only in his "word", that is, merely in a message or spoken phrase, but in his Word. The promise of eternal life is made manifest in--and, indeed, is completely identical with--Jesus Christ, the Word, who was in the beginning with God. He himself is God's promise of eternal life for us.
So that's pretty cool. But there's even more. John tells us that the Word was made flesh and dwelt among us. During that time, Jesus himself preached the good news: the Word preached the word. But then he ascended into heaven, leaving others to do the same thing in his place. That is why Paul says that the promise is manifested through his preaching, which God entrusted to him. This applies to all of us. So now both the Word and the word of the promise are manifested in our preaching, which we are commanded to do by God. So we preach the Gospel, and in so doing we preach Christ himself.
This is really cool. This is part of why we are called the body of Christ. Before, he himself walked the earth and was manifested to everyone who saw him. Now he is manifested through us. Just as Christ is the visible image of God, we are now the visible image of Christ, until such time as he comes again and "every eye shall see him."