It felt good to meditate. I haven't sat and meditated in weeks, maybe more. It was also a bit challenging as the focus happened to be the three characteristics, i.e., impermanence, suffering, and not-self. Theravada Buddhism sees nothing in the world as fixed, static. All is in flux. One could even say all is flux. The only 'permanent' is nibbana, which is permanent precisely because it's unborn, unmade, unconditioned, etc., meaning it lies outside of space and time and is free from conditionality, from change and flux.
This is one of the more difficult areas to reconcile Buddhism and Christianity, although it's not entirely impossible. Suffering arises when we cling on a deep, psychological level to that which is inconstant, when we base our happiness on things that have the nature to change. But when we constantly examine our sensory experience, we can begin to cultivate a sense of dispassion that cuts through our clinging and opens us to something transcendent.
Although the dominant belief in Theravada is that there's no soul or self to be found, and the Dhamma and experience of nibbana are talked about in impersonal terms, neither is said to be impermanent, and each contains aspects and functions commonly attributed to God. Moreover, other traditions do have teachings about our buddha-nature (tathagatagarbha) or true self, which is a positive expression of emptiness. While paradoxical, it's not unlike the way Erigena approached the paradoxical nature of God:
Erigena used the dialectical method of Denys in his own discussion of God, who could only be explained by a paradox that reminded us of the limitations of our human understanding. Both the positive and the negative approaches to God were valid. God was incomprehensible: even the angels do not know or understand his essential nature but it was acceptable to make a positive statement, such as "God is wise," because when we refer it to God we know that we are not using the word "wise" in the usual way. We remind ourselves of this by going on to make a negative statement, saying "God is not wise." The paradox forces us to move on to Denys's third way of talking about God, when we conclude: "God is more than wise." This was what the Greeks called an apophatic statement because we do not understand what "more than wise" can possibly mean. Again, this was not simply a verbal trick but a discipline that by juxtaposing two mutually exclusive statements helps us to cultivate a sense of the mystery that our word "God" represents, since it can never be confined to a merely human concept.
When he applied this method to the statement "God exists," Erigena arrived, as usual, at the synthesis: "God is more than existence." God does not exist like the things he has created and is not just another being existing alongside them, as Denys had pointed out. Again, this was an incomprehensible statement, because, Erigena comments, "what that is which is more than 'being' it does not reveal. For it says that God is not one of the things that are, but that he is more than the things that are, but what that 'is' is, it in no way defines." In fact, God is "Nothing." Erigena knew that this sounded shocking and he warned his reader not to be afraid. His method was devised to remind us that God is not an object; he does not possess "being" in any sense that we can comprehend. God is "He who is more than being" (aliquo modo superesse). His mode of existence is as different from ours as our being is from an animal's and an animal's from a rock. But if God is "Nothing" he is also "Everything": because this "super-existence" means that God alone has true being, he is the essence of everything that partakes of this. Every one of his creatures, therefore, is a theophany, a sign of God's presence. Erigena's Celtic piety—encapsulated in St Patrick's famous prayer: "God be in my head and in my understanding"—led him to emphasis the immanence of God. (A History of God, 198-99)
I find the similarities between the two ideas interesting, and I suspect that mystics as a group tend to share a common point of view and experience of the transcendent that's often overlooked because of the divergent terms and concepts these ideas and experiences are filtered through. I don't think that all religions are one, but I'm starting to think that all religious truths are, or at least they're pointing towards the same proverbial moon.