'The first resurrection,' mentioned in Revelation 20:5, 6, does not mean a first resurrection, but the essence and primary part of resurrection, which is salvation and eternal life. There is only one resurrection to life. A second does not happen, and is not mentioned anywhere in the Bible.

(References: Apocalypse Explained 6; Apocalypse Revealed 851; Revelation 20:5-6)

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.