This is a really good question. We've all seen it. Christians are supposed to be humble, giving of themselves and their time and resources to make the world a better place to be. It's often abbreviated by a call to "love and serve your neighbor." So why are some Christians so intolerably self-centered?
The short answer is that they shouldn't be.
Psalm 111:2 illustrates a fixation on God's works, not on ourselves. Our interest should be in what God is saying and doing. We can look a little farther, at Isaiah 40:21-31 and see what God's love is like. There we see a depiction of God's glory and the way he knows all about the world.
Psalm 147 describes many different actions of God. Those happen in plain view of God's people. We thus understand God's character based on His actions. This is what moves Christians to praise God, not to bring glory to themselves.
I 1 Corinthians 9:16 and 19, we read that the Christian has an obligation to tell the truth of God. Even though Paul is free of obligation in Christ, he also wants to bring the truth of God to all. Again, this puts the focus on God, not on Paul.
What are some of God's works that we focus on?
He is the creator and sustainer of all (throughout Paul's letter to the Colossians)
When the world falls into sin (Genesis 3, Romans 1:17 and following) He provides a means of reconciliation.
He loved the world and provided restoration in His own way (John 3:16).
He calls all to believe in what He does so as to receive life.
He proves his ability, among other ways, by. . .
providing abundance in what we need,
healing the sick
raising the dead
raising himself from the dead.
God makes many promises, including the promise of eternal life.
What do we do in light of this?
We look to God's Word to understand how He deals with us.
We gather with others to celebrate His work.
We receive His gifts in Word and Sacrament.
We pray that we will be instruments of His grace.
There, if we're busy with all that, we won't have time to be fixated on ourselves.
The visiting scholar asked me an interesting question. Why do Lutherans have nativity sets? Since I work as a missionary campus chaplain at a secular university, maybe I'd better set the scene more thoroughly. A nativity set is a set of figurines (sometimes small, sometimes large) depicting one or more elements of the birth of Christ. So there's usually a manger with a baby, a Joseph and a Mary figure, some farm animals, and sometimes shepherds and/or wise men who have come to visit. This visiting scholar was a Christian who had recently come to this country from China. She was intrigued by a local church which had a display of several hundred nativity sets.
The season of Advent and the prominence of the celebration of the Nativity is striking to many people. Within historic Calvinist settings, there won't be images depicting God, so they normally won't have such pieces of artwork. Many people from the more radical Reformation will avoid most elements of church history, so they might be unlikely to put an emphasis on the Nativity.
However, in Lutheran circles, because of our special theological emphasis, we're very likely to have things like nativity sets or other artwork depicting events in the life and ministry of Jesus. Unlike the Calvinist point of view and those which fragmented from Calvinism, Lutherans don't build their theology on the sovereign power of God. Rather, we focus on Jesus living and dying for you. The incarnation, then, is a really big deal.
Essentially we can recognize three basic perspectives coming from the time of the Protestant Reformation. One, generally held by those who would fall into a Zwinglian or Arminian perspective, would emphasize your responsibility to believe Jesus and follow him. Another, generally held by Presbyterians and other Calvinists, would emphasize God's sovereign desire to forgive sins for the elect. A third, held by Lutherans, is that Jesus is God with us, true man and true God so that he can live a fully human life and die a fully human death to atone for the sins of the world.
Are the other two points of view valid? The Bible clearly says we are supposed to believe Jesus and follow him. The Bible clearly shows God as the sovereign Lord of all who forgives sins. And the Bible leaves it crystal clear that Jesus is God with us. The elements of theology are true. However, the different groups of Christians start their theology in different places, so their theological buildings look different.
Back to the nativity sets, then? It's in the conservative Reformation, specifically Lutheran thought, that we find the emphasis on the incarnation. This makes our times of penitence, the seasons of Advent and Lent, specially vivid. We make a particular effort to recognize the sinfulness of sin, the fallenness of the world, and our need for a savior. Based on the incarnation of Christ, we also have a strong emphasis on the revelation of Jesus' work during the season of Epiphany, after Christmas and before Lent. Because we are focused on Jesus as God with us, during the Christmas and Easter seasons, we will have glorious depictions of Jesus, true man and true God, who was born for us, died for us, and lives for us. We will also pay special attention to the timeline of the ordinary season, between Easter and Advent, as we walk through the different elements of the Christian life in our Scripture readings. Jesus, God with us, has walked through just the same kind of things.
In the end, Lutherans focus on the incarnation. It's not about us, nor about a distant and theoretical view of God, but about Jesus, God with us.
That's why we looked at a few hundred nativity sets together. Jesus, the real God, was really born to save us.