The answer is: Father-in-law

John 18:13

In the Gospel of John, when we encounter Annas and Caiaphas, we step into a prominent corner of the Jewish leadership of the time. Annas was indeed the father-in-law of Caiaphas, which gives us a imaginative glimpse into this family’s political and religious machinations, pivotal leading up to the trial of Jesus.

Annas had served as High Priest before Caiaphas and, even after his formal office ended, he remained a powerful figure behind the scenes, a wise old fox of sorts, turning the wheels of influence. Throughout the New Testament, experience counts for a lot, and Annas certainly carried considerable weight due to his erstwhile position.

Fun fact: as a curious note in biblical history, Annas’ family monopolized the high priesthood during this period. There were a total of five of his sons who went on to become high priests. Having such a concentration power in one family was quite the dynamic in first-century Jerusalem!

From a literary perspective, look at how the narrative presents these two figures—it's laden with tension. Caiaphas famously recommended against healing Jesus out of political necessity, illustrating the tangled interplay of faith and authority. Lastly, this incident puts an interesting echo to the Matthew 10:36 verse, where kin can turn against kin in difficult times, reflecting severe personal and societal stakes surrounding Jesus’ fate.