"Neither pray I for these alone, but for them also which shall believe on me through their word; That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us." (John 17:20-21)
God and His Word are inseparable. God has revealed who He is through the Word. The scriptures declare that He created the universe by His Word. It's the power of God. He spoke and it was. St. John the beloved disciple of the Lord revealed by the power of the Holy Spirit that Jesus our Lord was the Word in flesh. He is the embodiment of God. St. Paul reveals that in the Lord Jesus the God head dwelt bodily. To understand the word Unity - look at the Father and Son. The Son of God then wanted this unity to percolate to those who would follow Him. He prayed to the Father for the first set of disciples and also for those who would believe on Him through their word. They should be One - this was and is the heartbeat of the Lord Jesus our Savior.
United in serving God, united in believing in Him, united in love. This is how a building is built physically too. Without the bricks being glued and cemented together, the building ceases to exist. It has to be connected to the foundations and roofs with the pillars and beams to support the structure. The church should showcase the unity we have in faith in the Lord Jesus Christ. The Word of God should be our standard where we grow in His purposes. The Apostles doctrine and lifestyle should also be our yardstick. As we stay united as the Father in the Son and the Son in the Father - we become one in the Lord. We effectively become the body of Christ. May we live our church life in accordance with this High priestly prayer of the Lord Jesus Christ.
For further reading: Ephesians 3:17-19, 1 Peter 2:5-7