Therefore for a Pagan to worship this Deity, Yahweh and Co., in all sincerity and fullness is rendering aid and comfort to an enemy: a Being who wishes Pagans destroyed or to have their religions and culture removed by conversion.
There are some qualifications to this statement: Rendering due honors in His hall is just being polite; He is a God after all. Attending the worship service of a neighbor, friend, associate, or family member in support of them is to be distinguished as well. That's just being respectful and caring. There are probably other times when doing something technically worshipful but which places persons over ideology and which are caring or honorable is appropriate. I can't be exhaustive. This requires good judgment.
The main problem is that Yahweh & Co., and Their followers, have declared themselves our enemies. We don't need to be out to destroy them to be enemies, because they already seek our destruction; that's what makes them our enemies. Worshiping any of the Three of Them is supporting the Deity that seeks to eliminate all of us "idolators" and "demon" worshipers. Ever been witnessed to? Have you seen the theocratic and Dominionist movements within Christianity? These are not aberrations attributable to a few bad apples, but central to the system of Christianity.
That some of the Christians you know are nice people says nothing about what Christianity and its God have in mind. This is a One True Way religion, not even slightly pluralistic. Perhaps you will raise the issue of interfaith work. Given Christian history, this behavior looks more like diplomacy defined as the art of saying "nice doggy" until you can find a big enough rock.
So, if you are Pagan, why would you worship Jesus Christ?
It is a good question: Why be Christian (i.e., worship Jesus Christ) at all? Besides its awful theology, to which we will return in a future post, worshiping YHWH or Son is a great way of having or retaining Christian privilege in our society. (See a great list of 40 Christian privileges from Schlosser, L. Z. (2003), "Christian privilege: Breaking a sacred taboo." Journal of Multicultural Counseling and Development, 31 (1), 44-51; more discussion here. It doesn't include my favorite: having your career advancement stopped because you are not Christian.) This behavior is tempting, but totally without integrity. There is nothing honorable about including any of Those Three in your worship just to have the cover and privilege they provide in our society.
Those of us who are actually Pagan have reason to resent this behavior. If you don't live our life, if you are unwilling to face the consequences and bear the burdens of being Pagan, don't call yourself one. This is the Pagan equivalent to a Native American saying to a non-Native, "Come live on the Rez, or stay out of our stuff" (in character if not intensity). Or in another frame, if you don't have African blood, do you get to say you are black-ish?
Historically, Paganism arose during the Florentine Renaissance as a critique and, in many cases, a rejection of Christianity. This critique is central to the character of Paganism and a major part of its value to the world. We are a direct corrective to the horror of Christian history, theology, and morals, none of which is good. (In the future, I will continue in this vein discussing why Pagan theology is superior to Christian theology.)
Magically, one might say we were invoked into being by the harmful actions of Christianity and its God as Their Nemesis. We are deeply entwined with the development of science and our technological culture, that culture which finally permits us to feed, clothe, shelter, etc., everyone on the planet (should we choose to). We are deeply entwined with the cultural transformation called the European Enlightenment by which the values of equality and democracy were established as central to our civilization.
Some will ask, what's wrong with mixing a bit of Christ in our Paganism? The Gospel story is not one of love and peace, that's just the public relations. The history of Christianity shows the true character of Christianity and its Deity: the destruction of civilizations and cultures, and the slaughter of innumerable humans as savages, infidels, or simply heretics. Then there is the subtler problem of Missionary Paganism, destruction by infiltration and dilution. They come and preach the nice stuff, and so we include Christian worship with ours, but slowly they teach that the Old Ways should be abandoned for Christianity. Eventually, only the old people know the old ways, and when they die off only Christians are left: the old ways are destroyed. Just ask the Indians of the Americas, just ask the Hawaiians, just ask the Africans.