From volume 5 of the works of Thomas Smyth (1808 – 1873), the following rules would help a lot of churches and Christians maintain the bond of peace. This advice is timely, even if it is around two hundred years old!

To remember that we are all subject ot failings and infirmities, of one kind or another
Matthew 7:1 – 5; Romans 2:21 – 23.

To bear with and not magnify each other’s infirmities.
Galatians 6:1

To pray one for another in our social meetings, and particularly in private.
James 5:16

To avoid going from house to house, for the purpose of hearing news, and interfering with other people’s business.
Leviticus 19:16

Always to turn a deaf ear to any slanderous report, and to allow no charge be brought against any person until well founded and proved.
Proverbs 25:23

If a member be in fault, to tell him of it in private, before it is mentioned to others.
Matthew 18:15

To watch against shyness of each other, and put the best construction on any action that has the appearance of opposition or resentment.
Proverbs 10:12

To observe the just rule of Solomon, that is, to leave off contention before it be meddled with.
Proverbs 17:14

If a member has offended, to consider how glorious, how God-like it is to forgive, and how unlike a Christian it is to revenge.
Ephesians 4:2

To remember that it is always a grand artifice of the Devil, to promote distance and animosity among members of Churches, and we should, therefore, watch against every thing that furthers his end.
James 3:16

To consider how much more good we can do in the world at large, and in the Church in particular, when we are all united in love, than we could do when acting alone, and indulging a contrary spirit.
John 8:35

Lastly, to consider the express injunction of Scripture, and the beautiful example of Christ, as to these important things.
Ephesians 4:32; I Peter 2:21; John 8:5, 35