How do we know that salvation must occur according to Scripture?

The concept of 'must' found in Scripture indicates an absolute necessity rather than a potentiality in salvation. For instance, 1 Peter 1:20 speaks of Jesus as the Savior who was foreordained before the foundation of the world, suggesting that the salvific work of Christ is not contingent upon human action but is established in God's eternal plan. This contrasts with the idea that salvation is merely a possibility. Biblical doctrine asserts that salvation is firmly rooted in God's purpose and will, revealing that those whom Christ came to save are indeed guaranteed salvation by His grace and power.