The Greek verb epangello (ἐπαγγέλλω) means to promise, to announce, or to profess. It appears 15 times in the New Testament. The related noun epangelia (promise/G1860) is one of the most theologically loaded terms in Paul and Hebrews. Together they represent God's self-binding commitment to His people.
The theology of divine promise (epangello) is the backbone of biblical theology. God promises Abraham a son (Romans 4:21), a land, a seed that will bless all nations. The entire Old Testament is the story of God's promise unfurling through history. The New Testament declares that "all the promises of God in him are Yes, and in him Amen" (2 Corinthians 1:20) — Jesus is the fulfillment of every divine epangello. Faith, in biblical terms, is trusting the one who promised.