Ein Sof?  In German, this means "the infinite."  We humans have great difficulty in grasping the essence of the infinite.  Indeed, in order to do so, we would need to spend an infinite amount of time to do so!  We'd never quite get there.  It's a bit like the Greek Stoic philosopher Zeno's paradox of the tortoise and the rabbit.  Although the rabbit can outrun the tortoise, given the infinite number of divisions between a beginning and end, it will never, technically, really outrun it!
     Our Jewish brethren often use Ein Sof to describe God.  God is so big and so incomprehensible that, they tell us, we're better off calling him simply "the infinite."  Regardless of how you might feel about God, you must admit the wisdom of this insight.  If God exists, and if he is worthy of our attention, then he must indeed be a presence whose magnitude immeasurably exceeds our own.
     Otherwise, he wouldn't be much of a God, would he?