It all depends if you think religion is about belief, values, or practice (or all three). Personally I believe in very similar ideas to many Unitarians with whom I have discussed theology (even Unitarian Christians). I believe that Jesus was a very special human being (along with Buddha, Gandhi, St Francis, Symmachus, and many other mystics and social activists). I believe that he carried the Divine spark, as each one of us do; perhaps his flame was a little brighter. I also believe that his values—of inclusivity, care, equality, community, and honouring diversity—were the most important thing about him, and that these values are what will save humanity from war, poverty and famine. So that’s why I am a Unitarian—I had a mystical encounter with him, and felt that his values were my values, and that Unitarianism puts those values into practice more effectively than many other forms of Christianity. At the same time I was reading a lot of liberation theology and queer Christian theology, all of which resonated strongly with me. I also believe (again in common with many Unitarians) that the Divine is in everything: the trees, the flowers, the Earth, you and me.
I am a Wiccan (and have been since 1991) because I believe that the Divine has one substance and many forms and faces, and I choose to honour it through Nature and through pagan mythology and the cycle of seasonal festivals. The values and beliefs of Wicca are also about inclusivity, tolerance, freedom and the wisdom of experience. Wicca honours both male and female forms of the Divine.
Both Unitarianism and Wicca celebrate being alive, present in this world and in this moment. Both agree that other religions are valid paths for those who choose them, and want to celebrate both individuality and community. And Unitarianism has included pagan elements since at least 1850, if not earlier (see The Larger View by Vernon Marshall).