What does the Bible say about apostasy and true believers?

In Hebrews 10, the Apostle Paul addresses the difference between apostates and true believers, asserting that apostates willfully neglect the gospel and turn away from God, often exhibiting a careless attitude toward the means of grace. In contrast, true believers are characterized by their enduring faith and an unwavering relationship with Christ which is rooted in His grace. The Apostolic exhortations encourage believers to draw near to God, hold fast to their hope, and encourage one another, which fosters spiritual growth and assurance in their salvation.