The noun hypostasis (literally 'that which stands under') is one of the most theologically consequential words in the New Testament, carrying the force of underlying reality and confident assurance. In Heb 1:3 the Son is the exact imprint of God's hypostasis -- his very being or essence -- making this term foundational to later Trinitarian theology. In Heb 11:1 faith is the hypostasis of things hoped for, variously rendered as 'substance' (KJV), 'assurance' (ESV), or 'confident reality.' Paul uses it in a different key in 2 Cor 9:4 and 11:17 to mean 'confidence' or 'basis for boasting.' German Wesen ('being, essence') and French substance together capture the word's two poles: objective reality and subjective certitude.