'Harmony' in the Bible

Grace to you and peace [inner calm and spiritual well-being] from God our Father and the Lord Jesus Christ.

For He Himself is our peace and our bond of unity. He who made both groups—[Jews and Gentiles]—into one body and broke down the barrier, the dividing wall [of spiritual antagonism between us],

Make every effort to keep the oneness of the Spirit in the bond of peace [each individual working together to make the whole successful].