Redeemer
Redeemer (go'el in Hebrew) was a legal term for the nearest male kinsman who had both the right and the obligation to act on behalf of a family member in need: to purchase back land that had been sold under economic distress, to marry a kinsman's widow to continue his name (levirate duty), and to avenge a murdered relative (blood avenger). The institution of the kinsman-redeemer is fully illustrated in the book of Ruth, where Boaz fulfills the role for Naomi and Ruth by marrying Ruth and redeeming Elimelech's land. The concept required the redeemer to be a blood relative with the means and will to act.
The Old Testament applies the title to God himself as Israel's supreme Redeemer: Isaiah uses go'el of the LORD more than twenty times, especially in the passages of consolation (Isaiah 41:14; 43:14; 44:6, 24; 48:17; 49:7, 26; 54:5, 8; 60:16). Job's great confession — I know that my Redeemer lives (Job 19:25) — anticipates a personal divine advocate who will vindicate him. The New Testament applies the full weight of this imagery to Christ, whose incarnation as a human being qualified him as the kinsman who could redeem humanity from bondage.