You've added the suspense, now where is the punchline? What is this spell you speak of. I'm just saying what everyone else is thinking, other than "...huh?" Lol.
What you're discussing is pretty much what all magick users strive for, but it's a lifelong commitment and can't be achieved through a single spell or ritual. In one way or another, we all strive to become whole (mind, body and soul/spirit). The most ancient of all symbols, the triangle, represents this connection.
The tree of life is another--a symbol of the interconnectedness of divine, physical and spiritual.
Witches and all magick practioners attempt or succeed in walking along the veil.