How do we know that only some people will go to heaven?

The concept of who will enter heaven is firmly rooted in Scripture, particularly in Revelation 21:27. It declares that those who enter the New Jerusalem are those whose names are written in the Lamb's book of life. This truth signifies God's sovereign choice in salvation, pointing to the reality that humanity, by nature, is unworthy. Romans 9 outlines God's sovereign will, stating that He has mercy on whom He wills and hardens whom He wills. This doctrine asserts that not all are destined for heaven; rather, it is those whom God has chosen before the foundation of the world, as Ephesians 1:4 emphasizes their predestined status. Thus, confidence in salvation rests in God's mercy, not human effort.