For the sake of simplicity, all quoted scriptures are taken from the New King James version.
"Behold, how good and how pleasant it is
For brethren to dwell together in unity!
It is like the precious oil upon the head,
Running down on the beard,
The beard of Aaron,
Running down on the edge of his garments.
It is like the dew of Hermon,
Descending upon the mountains of Zion;
For there the LORD commanded the blessing—
Life forevermore." - Psalm 133
"When the Day of Pentecost had fully come, they were all with one accord in one place. And suddenly there came a sound from heaven, as of a rushing mighty wind, and it filled the whole house where they were sitting. Then there appeared to them divided tongues, as of fire, and one sat upon each of them. And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit gave them utterance." - Acts 2:1-4
"Indeed it came to pass, when the trumpeters and singers were as one, to make one sound to be heard in praising and thanking the LORD, and when they lifted up their voice with the trumpets and cymbals and instruments of music, and praised the LORD, saying:
'For He is good,
For His mercy endures forever,'
that the house, the house of the LORD, was filled with a cloud, so that the priests could not continue ministering because of the cloud; for the glory of the LORD filled the house of God." - 2 Chronicles 5:13-14
" . . . that He might present her to Himself a glorious church, not having spot or wrinkle or any such thing, but that she should be holy and without blemish." - Ephesians 5:27
"But Jesus knew their thoughts, and said to them: 'Every kingdom divided against itself is brought to desolation, and every city or house divided against itself will not stand.'" - Matthew 12:25
"'When I shut up heaven and there is no rain, or command the locusts to devour the land, or send pestilence among My people, if My people who are called by My name will humble themselves, and pray and seek My face, and turn from their wicked ways, then I will hear from heaven, and will forgive their sin and heal their land.'" - 2 Chronicles 7:13-14
"There are diversities of gifts, but the same Spirit. There are differences of ministries, but the same Lord. And there are diversities of activities, but it is the same God who works all in all. But the manifestation of the Spirit is given to each one for the profit of all . . ." - 1 Corinthians 12:4-7
"I, therefore, the prisoner of the Lord, beseech you to walk worthy of the calling with which you were called, with all lowliness and gentleness, with longsuffering, bearing with one another in love, endeavoring to keep the unity of the Spirit in the bond of peace. There is one body and one Spirit, just as you were called in one hope of your calling; one Lord, one faith, one baptism; one God and Father of all, who is above all, and through all, and in you all." - Ephesians 4:1-5
"Therefore if there is any consolation in Christ, if any comfort of love, if any fellowship of the Spirit, if any affection and mercy, fulfill my joy by being like-minded, having the same love, being of one accord, of one mind." - Philippians 2:1-2