Per the above picture, we can illustrate the general, mathematical, concept of “union.” A concept all of us suffered through in high school math classes! :-))
Starting with two separate circles they are first joined in an “intersection.” Intersection is a partial overlap of the circles. Next (bottom), they are joined in a “union.” Union is a complete, 100%, overlap / blending of the two circles. At every point in the circle, they are brought together. It can be truly said that the two circles are now “one.” Obviously, I’m leading down a path to a biblical concept of union. And, yes, it will be shown to be the same as the mathematical concept shown here!
Consider the following list of unions that are seen in the Bible:
In the next chapter, each of these will be explained biblically.