Buddhism IS a religion. I have been a practicing Buddhist for many years. Buddhism relates that one of the causes of suffering is reliance on outside powers and the belief that we do not control our own destiny. The belief in a higher power is antithetical to Buddhism. Therefore, no, one can not be a Buddhist Christian or a Buddhist anything else. It is a self contained religion and one that is predominant in some parts of the world (Japan, Sri-Lanka). The term "religion" does not mean the belief in a god, but has that connotation because most western countries practice deity-based religions. Buddhism does at times appear to be a philosophy and/or a Science because it does not contradict either, nor does it shun modern thinking like many other religions. The ultimate goal, however, of Buddhism (and in my opinion, what should be the ultimate goal of all religions) is happiness in THIS world. That does not mean denial, or deprivation or rationalization, but actual results in the here and now. Buddhism has given that to me in abundance. So more than just a mere philosophy, it is an actual practical religion. In some sense one can say that all religions have a philosophical element to them. That is the underlying belief system that guides them. If one practices the guidelines of that philosophy, one can be said to "practicing" the religion. It's sort of like the difference between reading about exercise and actually doing it.