The old Welsh Prayer Book Eucharist lectionary for this day in Lent is Luke 11:1-13, which presents Jesus' teaching on prayer in response to the request of his disciples. It gives the shorter, perhaps more original version of the Lord's Prayer, as a guide to the subject content of prayer offered together, as well as alone. It continues more extensively to speak about the need for persistence and trust in prayer. In another passage about prayer in Luke 18 speaks of praying and not losing heart. My search for an image to reflect upon led me to this.
On a beach in Catalunya stand the remains of a fortified gun emplacement from the time of the Spanish Civil War. Once it guarded the road along the shore and the beach against invasion. Over eighty years, it has stood in the same place, unmoved. Tidal erosion has enlarged the beach, pushing back the line of the road, leaving the long abandoned fortification at the water's edge.
The constantly variable action of the sea mad this change happen. No two waves reaching shore are identical in shape and strength. No matter how alike they may appear at any time, they are but similar to each other. What binds their action into an unstoppable force for change is their persistence. They have been shaping earth's landscapes since seas first came into being.
Can such a quality of persistence be cultivated in seeking to pray and not lose heart? We know that the sea moves mountains eventually. In Mark 11:23, Jesus says:
"Truly I tell you, if anyone says to this mountain,
'Go, throw yourself into the sea,'
and does not doubt in their heart but believes
that what they say will happen,
it will be done for them.
It's not so much a literal promise of instant action, as an invitation to persist in trust that God's will shall be done, and as the sea teaches us, that means eventually.