What does the Bible say about assurance of faith?

In Hebrews 10:21-22, believers are encouraged to draw near to God with full assurance of faith, meaning their confidence is rooted in what Christ has done rather than their own efforts. This assurance allows believers to make sense of their existence, as it is through faith that they comprehend their purpose and eternal destiny in Christ. Ultimately, it is God's gift of faith that enables them to perceive spiritual truths that the natural man cannot understand, demonstrating how foundational assurance is to the believer's walk.