What does the Bible say about who will be in heaven?

Psalm 24 asks, 'Who shall ascend into the hill of the Lord? Who shall stand in his holy place?' The answer provided is 'He that hath clean hands and a pure heart.' This verse indicates that purity and righteousness are essential for admittance into heaven. However, the gospel reveals that this standard—while true—can only be met by one person: the Lord Jesus Christ. Through faith in Him, believers are granted the status of having clean hands and a pure heart because of His righteousness transferred to them.