The basis for the answer is found in a passage which is the actual Lord’s prayer, where Jesus is praying for His disciples in John chapter 17.
“I do not pray for these alone, but also for those who will believe in Me through their word; that they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me.” ~John 17:20-21
The same unity that Jesus had with His Heavenly Father is the exact type of unity He prayed we would experience and display so that the world would know He was sent from God. How did the world know He was sent from God? Because He didn't do His own will but followed the leading of His Father. How can we experience and display this same type of unity Jesus had with His Father? What was the link between them that made them operate as One?
"When all the people were baptized, it came to pass that Jesus also was baptized; and while He prayed, the heaven was opened. And the Holy Spirit descended in bodily form like a dove upon Him, and a voice came from heaven which said, “You are My beloved Son; in You I am well pleased.”" ~Luke 3:21-22
Is that same link available to us as a body of Believers??
"But you shall receive power when the Holy Spirit has come upon you; and you shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth.” ~Acts 1:8
YES! “…of the Spirit” is the link!
When we begin to follow and obey the leading of the Holy Spirit instead of doing our own will, we automatically come into unity with one another; and the world won’t be able to deny that Jesus lives through those who are called by His Name! Unity in the Spirit is all about the Spirit…endeavor to stay connected!
Seeking to Grow my Walk with God and Others,
*I decided to throw in the MMM's "Relationships Ever Abiding in Love" (R.E.A.L.) theme to remind us to be REAL in our unity with God and others.