What is the meaning of the word "ONE" in the Bible? In the Bible it talks of Jesus being one with the Father John 10:30 but also says that we should be one with them John 17:11. In the Bible's original Greek text, is the same word used for both, or is the word that describes our oneness with them different? The scriptures that speak of our heavenly Father and Jesus as being one are often used to prove the doctrine of the Trinity. (The Trinity being of one nature and one substance.) Does the original Greek word denote a physical oneness in substance, or a oneness in unity, purpose, action, and nature?
Working in unison, living in unity. 

Mark 10:8 8 


  and the two will become ·one body [as though they were one
  person; T one flesh; Gen. 2:24]’. So they are no longer two, but one.


John 10:16


  16 I have other sheep that are not in this ·flock [fold; pen; C a
  reference to future Gentile followers of Christ], and I must bring
  them also. They will listen to my voice, and there will be one flock
  and one shepherd.


John 10:30


  30 The Father and I are one.”


Judges 20:11 (ASV)


  11 So all the men of Israel were gathered against the city, knit
  together as one man. 


Oneness usually implies oneness of mind, actions, and so forth. 

1 Corinthians 1:10 (In contrast to modern setting.)


  10 But I urge and entreat you, brethren, by the name of our Lord Jesus
  Christ, that all of you be in perfect harmony and full agreement in
  what you say, and that there be no dissensions or factions or
  divisions among you, but that you be perfectly united in your common
  understanding and in your opinions and judgments.


Colossians 3:13-14 (Note relationship between love and unity (oneness))


  14 And above all these [put on] love and enfold yourselves with the
  bond of perfectness [which binds everything together completely in
  ideal harmony].


In a deeper sense, just as a Husband and Wife are ONE through a God-ordained arrangement, the Christ is ONE with the congregation. This principle is especially important, because its necessary in saving through unity: 

1st Corinthians 7:14 (Note the saving aspect of oneness)


  14 For the unbelieving husband is sanctified in the wife, and the
  unbelieving wife is sanctified in the brother: else were your children
  unclean; but now are they holy.


In this way the congregation (Christ's bride, loved as his own body) is also cleansed by the Christ due to marital contract and attains everlasting life. 



Conversely, the "Harlot" separating, disuniting from the Christ, unifying with Satan's world, becomes one with the world, and they share sins all the way back to Abel's murder.  Luke 11:51, Revelation 17:2 COMPARE TO: 1 Corinthians 6:16