Some people I call Christmas Christians. The most important thing about their Christian faith is believing that the Baby Jesus is Immanuel, God with us. Their favorite hymn is "Joy to the World."

Others I'd label Lenten Christians, whose faith revolves around sin, guilt and forgiveness. Their symbol is the cross.

Then there are Pentecost Christians, on fire with the Spirit's energy and gifts.

I'm an Advent Christian. I appreciate my brother and sister Christians, but I have a different way of seeing and experiencing the faith.

Advent Christians believe Christ came, but still we sing "Oh, Come, Oh, Come, Emmanuel." We believe that in Christ the kingdom of God has dawned, but still we eagerly pray "thy kingdom come" because we long for a world that is still to come. Exile, longing, watchfulness and waiting resonate with us.

For the four years I lived in Madagascar I was a "stranger in a strange land." Now, nearly 20 years later, I often feel like an alien in my own country -- a society dominated by economics and entertainment. The biblical words come back to me: "Here we have no abiding city. We seek one to come" (Hebrews 13:14).

I've lived a good life for more than 50 years, enjoying the blessings of family and friends, the beauties of the earth, the riches of art and music and our spiritual heritage. But at times I still ask, "Is that all there is?"

"If I find in myself a desire which no experience in this world can satisfy," wrote author C.S. Lewis. "The most probable explanation is that I was made for another world."

Our ultimate longing is really for God, for our true home. Advent Christians can't rest content. We long to be what we are not yet.

A critic of Christianity once said, "I would find it easier to believe in your Redeemer if his followers looked more redeemed."

Our longing is that what is true for us by faith may become true in experience. We believe Jesus when he said, "I am with you always, to the end of the age." But we often experience God's seeming absence. And so in Advent and throughout the year, Advent Christians remain thirsty for God. We know our sins are forgiven, but we want more; we want to become holy.

We long, too, for our society to live up to God's vision, for the kingdom to come in its fullness. The cry of Advent--"Wake up! Be alert! Watch for his coming"--startles me from spiritual drowsiness and apathy. But how do we stay alert when compassion fatigue, entertainments and busyness anesthetize us?

We can practice some simple--but not easy--disciplines. We can fast from the media to become more alert to the still small voice of God.

I have found, over 30 years, that keeping a journal helps me each day stay aware of what is truly important. I also can listen to that music, watch those movies, read those books that stab me awake rather than soothe me to sleep. Being awake I can pay attention to signs of God's comings.

In Advent we are called to wait for the coming of God and God's kingdom. Waiting is hard for me. One place I learn it is in my garden. I dig the ground, fertilize, plant the seed and water. Then I have to wait. No amount of impatience will make the plants grow faster. I wait in the hope of a harvest that I can neither see nor control.

As an Advent Christian, God's promises help sustain me in hope. I can accept my experience of exile and the existence of suffering in the world. I don't have to pretend that this life is all there is. I can live with my longings; I don't need to deny them. I can be mindful of the reality around me. I can sing of the reality to come.

And I can practice waiting. Then I'm ready to celebrate Advent, now, before Christmas and throughout my life, until the fullness of time, offering always this Advent prayer: "May the God of hope fill you with all joy and peace in believing, so that you may abound in hope by the power of the Holy Spirit."