What does the Bible say about certainty in salvation?

The Bible teaches us in 2 Corinthians 1:20 that all the promises of God are 'yea' and 'amen' in Christ. This means that if God promises something, especially regarding salvation, it is unequivocally true and will come to pass. Isaiah 55:7 reinforces this certainty: God promises mercy to those who forsake their wicked ways and return to Him, declaring that He will have mercy and pardon abundantly. The consistent message throughout Scripture is that when God speaks, we can trust in His word without uncertainty.