How do we know that God predestines people for salvation?

The doctrine of predestination is rooted in Scripture, most notably in passages like Ephesians 1:4-5, where it states that God chose us in Christ before the foundation of the world, predestining us for adoption as His children. This underscores God's sovereign choice and purpose in salvation, reflecting His grace and mercy. Additionally, Romans 8:29 mentions those whom God foreknew He also predestined to be conformed to the image of His Son. This indicates that predestination is not random but part of God's unchangeable plan to gather His elect.