Sin is a divider. That's what separated mankind from the Lord in the garden, and it has been fracturing relationships ever since. It's also the reason that God considers reconciliation so important. He wants to re-establish an intimate relationship with fallen humanity. But His desires for His children don't end with their salvation experience. He also wants His church to be a shining example of unity for all to see.
The last time Christ prayed for His followers before going to the cross, He asked "that they may all be one" as the Father and Son are one (v. 21). Despite the fact that we cannot attain perfect unity with God until we reach heaven, we do have the capacity to walk in harmony with Him by living in obedience to His Holy Spirit within us.
The other aspect of oneness that God desires for us is unity with one another within His church. We will always have differences in what we prefer and how we interpret certain Bible passages, but our common identity as Christians is based on the essential truths of the faith as revealed in God's Word. The unity Christ advocates is possible only when each member of His body walks in submission to the Spirit so that together they can achieve the purposes of God and reflect Christ's character in their behavior.
Ask the Lord to produce a desire for unity within your heart. When you're tempted to demand your own way, remember what's at stake. Accord in a local church allows God to do His work effectively through that congregation, but it's also an attractive witness that draws the lost world to Christ.