Just as the Father, the Son (the Word) and the Holy Ghost bear witness together in Heaven so also upon the earth three agree in the same beautiful unified manner: the Spirit, the water (the Word) and the Blood. This reveals that these are the three essential unifying elements in the church on the earth that agree together in the cause of unity in the church.
Unity through the Blood
Only through the Blood of Jesus Christ are we reconciled to God and are thereby unified together as His people. There is no peace, unity or agreement amongst men unless they have come through the blood-sprinkled way of redemption. Only those who through repentance and faith have lost all hope in religion, man and self can be unified. Only those who turn to and trust wholly in the Blood alone for their forgiveness, justification, redemption and sanctification can be made one. Only by blood can we enter into the covenant of grace and be made one in that covenant. Only the blood can deal with all enmity in our hearts and unite us with a holy God. So also only a blood-bought and blood-washed people can be united. The greatest divide in human history was between Jew and Gentile yet through the Blood of the Cross, Jew and Gentile were forged into one new man called the Body of Christ. We are not united by being nice to each other. We are not united by avoiding disagreements. We are only united because the Blood has dealt with our sin.
One of the most precious verses in the Bible about unity is Psalm 133:1, “Behold, how good and how pleasant it is for brethren to dwell together in unity!” Notice that it says “brethren.” Only spiritual brothers are united spiritually and only unity amongst brethren is blessed of God. Any unity between those birthed of God and those who are strangers to the new-birth is not a unity blessed of God. In the New Testament the term “brethren” means those birthed from the same womb. Christ in His ministry rejected all religion, good works, customs and religious tradition but pointed to the new birth, the born-again experience, a supernatural birth from above as the only means to bring sinners into the same family making them brothers. Only brethren are called to unity.