How do we know salvation is certain according to the Bible?

The certainty of salvation for those who believe is vividly illustrated throughout Scripture. In John 10:27-29, Jesus declares that His sheep hear His voice and cannot be plucked from His hand. This assurance is rooted in the divine promise of God, as seen in 2 Timothy 1:9, which states that God saved us according to His own purpose and grace given in Christ Jesus before the world began. Thus, believers can rest in the knowledge that salvation is not contingent on human effort but is a divine gift, secured by Christ's redemptive work on the cross. The expectation of God's unchanging nature ensures that those chosen in Christ possess eternal life.