Behold, how good and pleasant it is
when brothers dwell in unity!
2 It is like the precious oil on the head,
running down on the beard,
on the beard of Aaron,
running down on the collar of his robes!
3 It is like the dew of Hermon,
which falls on the mountains of Zion!
For there the Lord has commanded the blessing,
life forevermore. 
Theologian VanGemeren tells us, “The psalmist pronounces a blessing on those who “live together in unity.” During the pilgrimages, the Jews enjoyed an ecumenical experience on their way toward and in Jerusalem. The pilgrims came from many different walks of life, regions, and tribes, as they gathered for one purpose: the worship of the Lord in Jerusalem. Their unity was in conformity with the regulations for the three annual feasts (Exod 23:14–17; Lev 23:4–22, 33–43; Num 28:16–31; 29:12–39; Deut 16:1–17). During the feasts the Jews celebrated their common heritage: redemption from Egypt and their encampment.”
As we have been examining the unity enjoyed by the New Testament church, we can’t help but notice some similarities which apply to us today. Just as in our Psalm, the pilgrims came from different walks of life, regions, and tribes, so too the church enjoyed such unity and blessing because now the gathered assembly, although at the time was mostly Jewish converts, would carry the gospel message out from their place of worship to the far flung corners of the world, encompassing people from every walk of life. The early church wouldn’t be satisfied until all were reached. Out of their unity and efforts of the common life would arise, that which is pictured in the book of Revelation of every tribe, nation and tongue worshipping around God’s throne.
With so many denominations around the world today, some would say such unity is no longer possible, but I would disagree. It’s not one denomination or movement that is necessary for such unity to occur. After all the church in the Middle Ages, although one denomination was such a mess that it desperately needed renewal and reform. Unity has more to do with the attitude in each believer’s heart. Our problem seems to be that we don’t recognize the need for recognizing the things true believers have in common, irrespective of which denomination they may come from. The Psalmist and the New Testament and most of all, God still call for such unity of heart today. How pleasant and good that is!
 The Holy Bible: English Standard Version. (2001). (Ps 133:1–3). Wheaton: Standard Bible Society.
 VanGemeren, W. A. (1991). Psalms. In F. E. Gaebelein (Ed.), The Expositor’s Bible Commentary: Psalms, Proverbs, Ecclesiastes, Song of Songs (Vol. 5, p. 815). Grand Rapids, MI: Zondervan Publishing House.