"We wrestle not against flesh and blood, but...against spiritual wickedness in high places", Eph6:12. Against idol worship, filthy language, nasty behavior, and ignorance of the truth of God's Word.

Jacob wrestled the man (the angel, or epiphany) on the banks of the river and then received his new-name of Israel. Rachel wrestled her sister, Gen30:8, and afterwards became fruitful. When we wrestle with the Word of
God, and prevail to understanding, we become disciples too.

Nathanael believed on the basis of very little evidence, but some of us, like Thomas, are not so easily persuaded and have to see for ourselves.

Esau was the 'firstborn' and personifies the Old Man of the flesh, while Jacob personifies the New 'born-again' hidden man of the heart.