How do we know that faith in Christ is essential for salvation?

The biblical narrative consistently underscores the necessity of faith in Christ for salvation. In Luke 13:26-27, the individuals who are turned away from the door claim familiarity with Jesus, but He responds that He does not know them as His people. This highlights that mere outward actions or rituals do not suffice. True faith involves a personal relationship with Christ, characterized by genuine repentance and faith in His redemptive work. Ephesians 2:8-9 also stresses that we are saved by grace through faith, reinforcing the doctrine that salvation is a gift from God that cannot be earned through works.