This kind of devotion only comes out of a clear understanding of the Grace God has given. 

Ephesians 2:8-22

It is by Grace you have been saved. So that we can be one in Christ! Devoted to each other. 

Ephesians 5:1 Be imitators of God, therefore, as dearly loved children and live a life of love, just as Christ loved us and gave himself up for us as a fragrant offering and sacrifice to God

This is the WHY. This is the reason we are devoted. It is because of what Jesus has done for us.