Proverbs 27:17

"As iron sharpens iron, so one man sharpens another."

Men are sharpened for battle.  Just as a dull sword is useless in combat, so is a dull man.  And we know that our war is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. (Eph 6:12)  Men, we were not made to wage war against each other.  We are not each other's enemies but it is Satan himself who sows confusion among our ranks so that brother fights brother to tear each other down.  Brothers, this should not be!

We were made to sharpen each other as iron sharpens iron.  We were made to grow stronger together.  And now, it is Christ, the man of men, the king of kings, and the lord of lords, who has bound himself to us eternally by faith.  And when we are bound to him and bound to each other we will not fall but we will prevail against the enemy.  Your brother is not your enemy even though he may attack you.  Realize he needs the truth of Jesus Christ to set him free (John 8:32)  from the true enemy's grasp so that he may join you in the fight.

Do not hate your brother and tear him down, but build him up as a fellow soldier in Christ.  Offer him the Truth and set him free.

Philippians 1:27

"Whatever happens, above all else conduct yourself in a manner worthy of the gospel of Christ.  Then, whether I come and see you or only hear about you in my absence, I will know that you stand firm in one spirit, contending as one man for the faith of the gospel"

No matter what, we are in this together.  That is the message Paul is giving us in Philippians.   This is the first command he gives and it is also the most important.  Above all else, do this.  It is a call to unity and to endure together no matter what comes of him, whether he lives or dies in prison.  But why is it so important that the church be unified?

In John 17, Jesus Christ prays for all believers to be one just as He and the Father are one in order that the world would know that Jesus Christ is the Son of God.

It is through our unity that Christ proves his divinity.
It is our unity that shows the world that there exists a God in heaven who loves them.
It is our unity that brings about saving faith that Jesus Christ is the Son of God.
It not only saves others, but it saves us as well.

And so not only our salvation but the salvation of the entire world depends on the church standing firm together.