How do we know that salvation is guaranteed for believers?

In John 17, Jesus prays specifically for those whom the Father has given to Him, indicating a distinct group among humanity that is ensured salvation. The certainty of salvation is anchored in the sovereign grace of God, which guarantees that all whom the Father gives to the Son will come to faith. Jesus’ prayer is characterized by His confidence and power, underscoring that true believers are held securely by Him. This assurance is further supported by the theological concept of election, where God has chosen His people before the foundation of the world, demonstrating that their salvation is rooted in His sovereign will rather than human effort.