John 13:34 “A new command I give you: Love one another. As I have loved you, so you must love one another. 35 By this everyone will know that you are my disciples, if you love one another.”
Challies has an excellent post regarding how to keep unity among Christians. It is a summary of a chapter from Thomas Brooks’ book Precious Remedies Against Satan’s Devices.
The first two of the twelve are:
#1. Spend more time considering evidences of grace in other Christians than you do pondering their sins and weaknesses. You, as a Christian, probably have a much greater ability to see weakness in other believers than to see strength. It is as if you use a magnifying glass when looking for weakness and a telescope when looking for grace. Brooks warns, “Sin is darkness, grace is light; sin is hell, grace is heaven; and what madness is it to look more at darkness than at light, more at hell than at heaven.” Indeed.
#2. Consider that spiritual safety comes through spiritual unity. Christians united together are difficult to separate, difficult to break, difficult to pick off and destroy. It is when you isolate yourself by disrupting or denying unity that you are most at risk.
Find the rest here
How we need to keep the call for unity with believers more seriously. I once asked my father after he had been in the pastorate for almost 60 years what he wanted to happen in the church. He replied “I want the man on that side of the church to reach across the aisle and take the hand of the man on this side of the church”. Sixty years in the ministry and what grieved him the most was the lack of Christian love between those who claim to be loved by Christ. Oh how we need to love other believers.
I John 3:11 For this is the message you heard from the beginning: We should love one another. 12 Do not be like Cain, who belonged to the evil one and murdered his brother. And why did he murder him? Because his own actions were evil and his brother’s were righteous. 13 Do not be surprised, my brothers and sisters, if the world hates you. 14 We know that we have passed from death to life, because we love each other. Anyone who does not love remains in death. 15 Anyone who hates a brother or sister is a murderer, and you know that no murderer has eternal life residing in him.
16 This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers and sisters. 17 If anyone has material possessions and sees a brother or sister in need but has no pity on them, how can the love of God be in that person? 18 Dear children, let us not love with words or speech but with actions and in truth.