What does it mean to be 'in Christ' according to the sermon?

'In Christ' signifies a believer's union with Jesus, which invites the fullness of God’s blessings in their lives. This relationship is foundational for understanding a Christian's identity and assurance of salvation. The phrase emphasizes that true believers are blessed in life, death, and eternity, underscoring that salvation is entirely through Christ's work. As mentioned in the sermon, the tombstone from 1833 encapsulates this truth, affirming that all who have a saving interest in Christ enjoy profound blessings through Him. Placing faith in Christ is transformative; believers live with the assurance of God’s promises and eternal security.