Although Reiki is not a religion or directly affiliated with any religion, some Christians are hesitant to practice or receive Reiki for fear that it is incongruent with their faith. This is understandable. The use of energy techniques for healing is not something that is often talked about in church.
However, there are also many Christians that do practice and receive Reiki and believe that this is one aspect of what healing through the laying on of hands means. They believe that all healing comes from God, so any practice that has a healing effect must be of God.
Although the US Catholic bishops have urged Catholic hospitals not to support the use of Reiki, there are many other Christians—both Catholic and Protestant—who use Reiki as part of their ministries. This is obviously an area that not all Christians agree on, and each person must make their own decision about what they believe.
There is a website called Reiki for Christians that was created by Christians who do practice and receive Reiki that answers many questions that Christians may have. It contains stories from people who use Reiki, articles about Reiki and Christianity, frequently asked questions, and information about the ways they believe Reiki and Christianity are compatible.
If you are a Christian and are unsure what you believe about this practice, this is a great website to learn more to help you come to your own conclusion.