In John Piper’s book A Peculiar Glory, he makes the case that our spiritual perception of God’s glory in the Bible is the ultimate, unshakable ground of our trust in the Bible’s truthfulness (see a summary of his argument here). He points out that 2 Corinthians 4:3–6 says the Gospel “is veiled to those who are perishing”; they’re spiritually blind, unable to see “the light of the Gospel of the glory of Christ, who is the image of God.” And (v. 6) it’s when God gives us “the Light of the knowledge of the glory of God in the face of Christ”—that is, when we’re enabled to see the glory of Christ revealed in the Bible—that we love Him, come to Him, and are saved.
Though the book focuses on how this idea relates to the Bible’s revelation of Christ’s glory, in the passage below Piper applies it to how we ought to go about telling others about Jesus, explaining how we, also, can reveal Christ’s glory.
If the true ground of faith is “the glory of God in the face of Jesus Christ,” then proclamation that aims at faith should be a vivid and true portrayal of the glorious Christ. People must come face-to-face with Christ in what they hear or read….
He set aside his rights as God to take on the form of a slave and humbly die in obedience to his Father (Phil. 2:6–8). Though he was rich, yet for our sakes he became poor (2 Cor. 8:9). He did not please himself but took the reproaches of men that he might accept us into his fellowship to the glory of God (Rom. 15:2, 7)….
[T]he person who proclaims the Lord of glory is a slave for Jesus’s sake of those he is seeking to persuade: “For what we proclaim is not ourselves, but Jesus Christ as Lord, with ourselves as your servants for Jesus’ sake.” In other words, the proclaimer embodies the beauty of the proclaimed. He freely lays down his God-given freedom and takes up the role of slave and puts himself at the disposal of others for their good (Phil. 2:5)….
The promise that the apostle John gives in his first letter, that “when Christ appears we shall be like him, because we shall see him as he is” (1 John 3:2), is already being fulfilled, as we behold the glory of Christ in the gospel. That is what Paul is saying in 2 Corinthians 3:18. We tend to become like those we admire. This means that we, like him, set aside our rights and do not seek to please merely ourselves, but rather we become servants for the benefit of others. Beholding the beauty of Christ’s character, we begin to share it.
The purpose of this transformation into a self-giving servant role is to provide another display of the glory of God as the ground of faith—an embodied display. So we present the glory of Christ not only in our gospel but also in our lives. While proclaiming the light of the knowledge of the glory of God in the face of Christ, we also become the light of the world, so that men may see our good deeds and glorify our Father who is in heaven (Matt. 5:16). If we see and love the glory of God in Christ and are being transformed by it, we become a mirror of that glory and a means to the well-grounded faith of others.
I’ve written before about how the biggest divide between Christians and non-Christians is not whether or not they think Christianity is true but whether or not they think Christianity is beautiful—and specifically, whether or not they think Jesus is beautiful. This is why your use of apologetics always needs to not only focus on honoring Christ but also to incorporate your entire life as an apologetic for the character of Christ. Everything we say and do is an opportunity to reveal His glory to others.