Read the remarkable document known as “To The Hebrews” in the New Testament.
In it, the author provides detailed and lengthy argumentation regarding Jesus Christ being the fulfillment of all the hopes of the patriarchs and faithful of old, and why the work of the Son (before, during, and after the Incarnation) is indispensable for salvation.
To The Hebrews is one of the most important texts in all of scripture, although tradition has not passed down the identity of its author.