Why is Christ important for Christians' assurance?

Christ is essential for assurance as He is the embodiment of God's fullness and serves as our covenant surety. As stated in Colossians 2:9, 'For in Him dwelleth all the fullness of the Godhead bodily.' This means that all aspects of God's character and attributes converge in Christ, making Him the source of our assurance. His perfect sacrifice also satisfies divine justice, ensuring that believers are justified and accepted in Him. Without Christ, there can be no true understanding of salvation or assurance of our eternal security.