Unity in Christ

How do we see that everything God has ma de is ordered? How is the leaven of the church in our hearts? How is Christ the Unity of His church? How is Christ the ‘only begotten Son’? How are we only able to be called brethren because we are ‘in’ Christ? Why should we be careful not to compare ourselves to another? What is the significance of the High Priest being anointed and how does it picture Christ and His righteousness earned in His obedient flesh? Why was Christ baptized?