Jesus healed them because of their faith.
the pilgrimage and washing with water is our human way to show that we have faith in Jesus when we request healing.
A lot of time, the healing in Lourdes is the peace in the soul of those who are not healed physically. The peace of Christ, who is present in their soul.
Not all suffering is physical: Spiritual and psychological suffering is worse, and indeed makes physical suffering worse.
Why some are healed but not others? A variation of why is there suffering, and why do good people suffer.
No easy answer: except to say Jesus suffered like us and is with us in our suffering, and that we can offer our sufferings as a prayer, and God will wipe our tears away in heaven.
one of my medical school professors told us that few doctors are pious, but few are atheists: because we see people who scientifically should have died, but live, but also people who should live but die despite all of our efforts. And if we didn’t have faith that there was a pattern or ultimate plan behind our lives, we would not be able to function.
So I think we’re both in agreement that God does heal. When it is His will, not our will. And He can will our healing anywhere, anytime. There are no magical waters or statues or candles or peopie that are vessels of healing. Is that correct? If so, then why are pilgrimages made to places like Lourdes for healing? Unless they believe the water is magical. Why do they send for holy water? Unless they believe the water is magical? Same thing with relics of the dead, Turin, etc.?