In John’s readings from the Last Supper today and tomorrow, Jesus’ disciples , Thomas and Philip, appear unsure of the way and the power of Jesus himself. An important question raised in mystagogic catechesis.

 St. Ambrose in the 4th century met the same uncertainty of signs as he spoke to the newly baptized of his time. They signify so much, but we find them hard to accept. “Is this it?” he hears them say as they approach the waters of baptism and the table of the Eucharist.

Encountering God through sacraments in weakened further today by a lack of a symbolic sense, Pope Francis writes in his letter Desiderio Desideravi . Now, more than ever, human beings, like Thomas and Philip, want to see. We want immediate experience.

Ambrose calls on stories of the Old Testament. The Israelites were saved as they flee from Egypt through the waters of the Red Sea, the cloud that guides them on their way–foreshadowing the Holy Spirit, the wood that makes the bitter waters of Marah sweet–the mystery of the Cross.

“You must not trust, then, wholly to your bodily eyes. What is not seen is in reality seen more clearly; for what we see with our eyes is temporal whereas what is eternal (and invisible to the eye) is discerned by the mind and spirit.” (On the mysteries)

The Assyrian general, Naaman, doubted as he stood before the healing waters of the Jordan, Ambrose reminds his hearers. There’s more here than you see or think.

So we’re invited into an unseen world. Still, we’re like those whom the gospel describes and the saint addresses. Is this it? Moreso now, schooled as we are in the ways of science and fact, we look for proof from what our eyes see. We live in a world that tells us what we see is all there is.

Faith is a search for what we don’t see. God desires to approach us through signs. Will he not help us approach him that way? Believe in me, Jesus says.

Readings here.