How do we know Jesus Christ is our eternal salvation?

Hebrews 5:9 clearly states that Christ, having been made perfect through His suffering, became the author of eternal salvation to all who obey Him. This encapsulates the essence of sovereign grace—our salvation is wholly dependent on Christ’s completed work. Unlike the law, which demands our performance, Christ's priesthood after the order of Melchizedek signifies a new covenant where He fulfills the law on our behalf, and thus, our hope for salvation rests solely in Him. This distinction is crucial; salvation is not a result of our efforts but is a gracious gift from God, secured by Christ’s sacrifice and resurrection, ensuring that those who are truly His will persevere in faith.