How do we know that justification is from eternity?

Eternal justification asserts that God justified His elect from eternity, meaning that this declaration did not occur at the moment of faith or at the cross but was determined in God's eternal counsel. This is supported by passages like Ephesians 1:4-5, which states that believers were chosen in Christ before the foundation of the world. God's omniscient nature means He views all things outside of time, thus the justification of the elect was established before creation. This emphasizes the certainty of God’s plan for salvation, demonstrating that the work of Christ was always the basis for righteousness and that all of the elect were viewed as justified in God's sight long before they were born or even sin committed.