One of the ways we can investigate whether an ancient document is historically reliable is to find corroboration of its claims in archaeological findings. Because the Gospel of John was written in the first century AD, we can look to findings dated in that time period to corroborate details recorded in the Gospel. How does the Gospel of John fare?

According to Andreas Kostenberger, in John, Acts: Volume Two (Zondervan Illustrated Bible Backgrounds Commentary), there are fourteen major archaeological findings that corroborate the Gospel of John. These include: 1) an inscription barring Gentiles from the temple, 2) Herod’s temple, 3) Jacob’s well, 4) Pool of Bethesda, 5) ancient fishing boat, 6) early synagogue, 7) Pool of Siloam, 8) Siloam inscription, 9) tomb of Lazarus, 10) Caiaphas tomb/inscription, 11) Pilate inscription, 12) stone pavement, 13) skeletal remains of crucified man, and 14) and garden tomb.

Let’s look specifically at the Pool of Bethesda. Walter Kaiser and Duane Garrett, in the NIV Archaeological Study Bible, describe what archaeologists have discovered.

The pool at Bethesda was a familiar locale among the Jews of Jerusalem. It was mentioned, for example, in Qumran’s Copper Scroll as the ‘place of poured out water.’ It was located near what are now the ruins of the basilica of Saint Anne to the north of the temple mount. The ‘pool’ was actually two pools surrounded by four porticoes, with a fifth portico situated between them. Coupled with the elegant porticoes, the pools must have been an impressive sight. While the lavish complex of John’s day likely dated to the reign of Herod the Great, the pools were probably in use before that and may have been the site of an intermittent spring.

The Biblical Archaeology Staff provide additional details in their article entitled “The Bethesda Pool, Site of One of Jesus’ Miracles.”

When Jesus heals the paralytic in the Gospel of John, the Bethesda Pool is described as having five porticoes—a puzzling feature suggesting an unusual five-sided pool, which most scholars dismissed as an unhistorical literary creation. Yet when this site was excavated, it revealed a rectangular pool with two basins separated by a wall—thus a five-sided pool—and each side had a portico.

The Jesus miracle story also tells how many people sought the Bethesda Pool’s healing powers. The first person to enter the pool when the waters were stirred up would supposedly be cured of his or her ailment. But, the paralytic tells Jesus, he can never get into the water quickly enough. So Jesus immediately cures him, and he is able to get up and walk.

This story about Jesus’ miracle suggests a long history of healing at the site. Roman medicinal baths constructed at the Bethesda Pool only a century or two later reflect this continued tradition. When Christians controlled Jerusalem in the Byzantine and Crusader periods, they liked to mark the sites of Jesus’ miracles and other important events in his life, so they added a chapel and churches that now cover the Bethesda Pool complex.

So why a pool with two basins? The archaeological evidence shows that the southern basin had broad steps with landings, indicating that it was indeed a mikveh. The northern basin provided a reservoir, or otzer, to continually replenish and repurify the mikveh with fresh water flowing south through the dam between them. Jerusalem’s pilgrims would flock to the Bethesda Pool and Siloam Pool to purify themselves in these public mikva’ot and, at times, to seek healing.

Archaeological findings, like the Pool of Bethesda, give us confidence that the author of the Gospel of John was an eyewitness of the events he was reporting, and, therefore, in a good position to report what actually occurred.