Who hath also sealed us, and given the earnest of the Spirit in our hearts. 2 Corinthians 1:22
"A fascinating example comes to mind. Paul writes to his community at Corinth “he [God] has put his seal upon us and given us his Spirit in our hearts as a guarantee” (2 Cor 1:22). The word translated here “guarantee” is the Greek word arrabon (arrabwn).
It is actually a word of Semitic origin and is used in Gen 38:17 for a “pledge.” However, it gets picked up in the Greek world and we have many examples of its usage. It is actually an economic term that refers to a “down payment” or a “first installment” in a purchase. That is why the King James Version translated it “earnest,”—like the “earnest money” in a real estate deal.
It is also used in the surviving Greek papyri in connection with an engagement ring—a pledge of marriage. One of our most valuable and fascinating sources for understanding the Greek contemporary with the writing of the N. T. documents are the papyri. These are the hundreds of thousands of scraps of letters, receipts, notes, and other documents, both formal and informal, that have survived, mostly in “garbage dumps” in Egypt where the climate is dry.
These texts offer us many examples of the ways in which words, so common in the New Testament, are used in the contemporary culture, often in an “everyday” context. For example the word euangelion (euangelion), or “Gospel,” which Christians properly hold sacred, is actually a common Greek term for “good news,” and is even used in a Greek inscription that survives at Ephesus in connection with the emperor Augustus Caesar and his policies in the eastern Mediterranean."