How does God's grace play a role in our union with Christ?

Our union with Christ is entirely a work of God's grace. According to Ephesians 1:4-5, God chose us before the foundation of the world and adopted us as His children through Jesus Christ. This unmerited grace means that our salvation, our being placed in union with Christ, and our ongoing relationship with Him are not based on our performing or striving but solely on His merciful act of choosing and calling us. It's a comforting assurance that we are secure in Him, as His grace sustains us in all aspects of our Christian walk.