How do we know that faith is essential for entering God's rest?

Hebrews 4 clearly outlines the necessity of faith for entering into God's rest, echoing the idea presented in 4:2 that the gospel was preached to the Hebrews, but it did not benefit them because it was not mixed with faith in those who heard it. This highlights that, while the message of salvation is universal, it requires an active believing response from individuals to be effectual. The act of believing is not something we conjure up by ourselves; it is a gift from God, enabling us to trust in the work of Christ. Thus, the faith given by God allows believers to rest from their striving for righteousness, as they rely solely on Christ's finished work.