How do we know there will be a judgment day?

The doctrine of the final judgment is emphasized throughout Scripture, particularly seen in Romans 2:16, where it says, 'In the day when God shall judge the secrets of men by Jesus Christ according to my gospel.' This judgment day is fixed, and no one knows when it will occur, but it is assured by God's sovereignty. Additionally, John 5:22 declares that 'the Father judges no man, but hath committed all judgment unto the Son.' Therefore, believers and non-believers alike will stand before Christ, who is both God and our mediator, to give an account of their lives.