All changes of place in the Bible represent changes in spiritual state. “Entering” – usually used as entering someone’s house or “going in unto” someone – particularly means adopting a spiritual state that is compatible with someone else in order to communicate with them or be conjoined with them. This is easily seen in the fact that a man “going in unto” a woman is sort of a Biblical euphemism for a physical relationship. In a broader sense, all the spiritual changes we go through in our lives involve “entering” and “leaving,” so when the Bible uses the phrasing “going in and coming out,” it symbolizes someone’s entire spiritual life.

To enter, as in Genesis 7:1, signifies to be prepared.

A company might have executives setting policy and strategy, engineers designing products, managers handling personnel and others handling various functions. They all do different things -- but if they're doing them with a shared underlying purpose, the company -- and the individuals in it -- will likely be successful. The Lord wants all human society to function in a similar way. We have different skills and individual loves, but if we all share a mutual love -- a love of serving others -- then society will function as one, will be a reflection of heaven and will be a good receptacle for the Lord's love. This can also happen within each of us, as we unify our talents and ideas around a central love. And in an abstract sense, it illustrates how a wide collection of varying ideas can be unified around a shared good intention. That is the kind of love pictured when “one” is used in the Bible, either as a specific number or in the sense of several people or objects “being one.” In more casual references -- when used to identify a specific person or object -- the meaning is relatively literal, and is connected to that person or object.