Charles H. Spurgeon on Psalms 133:1

Together in unity. If there be but one God, as God is one, so let them that serve him be one. This is what Christ prayed so heartily for. "That they may be one:" Joh 17:21. Christians should be one, 1. In judgment. The apostle exhorts to be all of one mind. 1Co 1:10. How sad is it to see religion wearing a coat of divers colours; to see Christians of so many opinions, and going so many different ways I It is Satan that has sown these tares of division. Mt 13:39. He first divided men from God, and then one man from another. 2. One in affection. They should have one heart. "The multitude of them that believed were of one heart and of one soul": Ac 4:32. As in music, though there be several strings of a viol, yet all make one sweet harmony; so, though there are several Christians, yet there should be one sweet harmony of affection among them. There is but one God, and they that serve him should be one. There is nothing that would render the true religion more lovely, or make more proselytes to it, than to see the professors of it tied together with the heart strings of love. If God be one, let all that profess him be of one mind, and one heart, and thus fulfil Christ's prayer, "that they all may be one." —Thomas Watson.