It's a question that we get from UUs, and it's a question we often pose to ourselves.
The first answer is--sometimes we do go down the street. In my own Christian fellowship, over time members have discovered, or rediscovered, Christianity and either have left the UU congregation for a Christian one or are exploring the Christian experience in other churches as part of their search. For years, I attended two churches--Episcopalian and UU. This is actually a fairly common practice and a good fit for progressive Christians.
When my Christian Fellowship began to take "field trips" to local Christian churches, someone asked, "What do you expect to do? Leave the UU Church?" And we decided our answer was ,"No." Because we have the second set of answers to why we don't go down the street.
- Theology. Even in more liberal Christian denominations, some tenets remain stable. Jesus is divine; Jesus died for our sins; salvation may not be universal; our reward is in Heaven. These tenets may not be overt, but discussions in the church will revolve around the religion about Jesus vs. the religion that Jesus taught. For many of us, who follow the religion Jesus taught, this conversation is not where we are in our journey.
- Orientation. This is probably more compelling, not just for Christians, but also for Buddhists, Jews, and others coming into UUism from another denomination or religion. The UCC would probably argue with some vigor at the comment that the UCC has "Christianity added". The point of Christian churches is to put Christ in the center. The point of the UU churches is to put a covenant of Principles in the center. We are UUs; we are drawn to the covenantal approach of living together.
- Religious Pluralism. Again, we UU Christians are UUs. We affirm and promote spiritual seeking and we cherish the faith diversity in UU congregations.
For illustration. A Methodist seminarian intern working at the UUA and joining the UUCF Revival last year commented that he couldn't imagine a service in which the Bible was not read. For us UU Christians, we could imagine it, we experience it, and we revel in it.
As UU Christians, we get a kick out of the spiritual conversations we have with our fellow UUs who see the One Light through a different window. We like being challenged by the UU principles and diverse spiritual paths as well as by other progressive Christians. I think we're a bit greedy--we want to have our cake, eat it, and then lick the frosting from the plate.
Some of us may choose to "go down the street", but many of us will stay right in our UU congregations, while continuing to broaden our experiences and feed our inner spirits, using every tool available to us.
May all our spiritual journeys be diverse, rich and fulfilling. Blessings!