See also: D&C 35:2
We could progress a great deal faster, and could prosper a thousand times more than we do if we would be one in carrying out the counsels given us by the Lord through his servants. — President John Taylor
Could we all come together with one heart and one mind in perfect faith the veil might as well be rent today as next week, or any other time. — Joseph Smith
Some members assume that one can be in full harmony with the spirit of the gospel, enjoy full fellowship in the Church and at the same time be out of harmony with the leaders of the Church and the counsel and direction they give. Such a position is wholly inconsistent, because the guidance of this Church comes not alone from the written word but also from continuous revelation, and the Lord gives that revelation to the Church through His chosen prophet. It follows, therefore, that those who profess to accept the gospel and who at the same time criticize and refuse to follow the counsel of the prophet are assuming an indefensible position. Such a spirit leads to apostasy. It is not new. It was prevalent in the days of Jesus and in the days of the Prophet Joseph Smith.
The way to unity is for us to learn the will of the Lord and then to do it. Until this basic principle is understood and observed, there will be no unity and peace on the earth. The power of the Church for good in the world depends upon the extent to which we, the members thereof, observe this principle. — President Marion G. Romney, General Conference, April 1983; Church News, March 10, 2001, p. 14
The miracle of unity is being granted to us as we pray and work for it in the Lord’s way. Our hearts will be knit together in unity. God has promised that blessing to His faithful Saints whatever their differences in background and whatever conflict rages around them. He was praying for us as well as His disciples when He asked His Father that we might be one.
The reason that we pray and ask for that blessing is the same reason the Father is granting it. We know from experience that joy comes when we are blessed with unity. We yearn, as spirit children of our Heavenly Father, for that joy which we once had with Him in the life before this one. His desire is to grant us that sacred wish for unity out of His love for us.
He cannot grant it to us as individuals. The joy of unity He wants so much to give us is not solitary. We must seek it and qualify for it with others. It is not surprising then that God urges us to gather so that He can bless us. He wants us to gather into families. He has established classes, wards, and branches and commanded us to meet together often. In those gatherings, which God has designed for us, lies our great opportunity. We can pray and work for the unity that will bring us joy and multiply our power to serve. — President Henry B. Eyring, “Our Hearts Knit as One,” Ensign, November 2008
If we, in our wards and our branches, are divided, and there are factions not in harmony, it is but an evidence that there is something wrong. If two persons are at variance, arguing on different points of doctrine, no reasonable, thinking persons would say that both were speaking their different opinions by the Spirit of the Lord. . . .
If it is so important, then, that this people be a united people, we might well expect that
upon this principle the powers of Satan would descend for their greatest attack. We might well expect, also, that if there be those of apostate mind among us, they would be inclined to ridicule and to scorn this principle of oneness and unity as being narrow-minded or as being unprogressive. We would likewise expect that those who are enemies would also seek to fight against that principle. . . . — President Harold B. Lee, Conference Report, April 1950, pp. 97-98
It is the principles of truth which cement us together and make us act in union and strength; it is those principles that buoy up our feelings, animate our souls and make us feel joyous and jubilant under all circumstances; it is light, it is truth, it is intelligence, it comes from and leads to God, exaltation and celestial glory. We feel joyous because we have the principles of eternal life within us; it is because we have partaken at the fountain of life, and know our relationship to the Lord. — Teachings of Presidents of the Church: John Taylor, p. 92