What is the mystery of union in Christ?

The mystery of union in Christ speaks to the profound and eternal relationship between Jesus and those chosen by God. Ephesians 1:4 indicates that God's elect were chosen in Him before the foundation of the world, illustrating that there is a spiritual union that binds Christ and His people together. This union manifests in various ways, including the believer's identification with Christ's death and resurrection, as noted in Galatians 2:20. While this union is rooted in eternity, it also becomes experiential in time as believers come to faith, symbolizing the vital connection established through the Holy Spirit.