…by the way of the sea, beyond Jordan, Galilee of the Gentiles… and to them which sat in the region and shadow of death light is sprung up. – Matthew 4:15-16
Men who know not the truth, since they must have some faith, seek out many inventions; for, if they are not taught of God, they soon become taught of Satan, and apt scholars are they in his school. Galilee was noted for the heresies which abounded there. But what a mercy it is that God can save heretics. Those who have received false doctrine, and added darkness to darkness in so doing, can yet be brought into the glorious light of truth. Though they may have denied the Deity of Christ, though they may have doubted the inspiration of Scripture, though they may have fallen into many traps and pitfalls of false doctrine, yet the Divine Shepherd, when He seeks His lost sheep, can find them out and bring them home again.
In consequence of being in the darkness of ignorance and error, these people were wrapt in the gloom of discomfort and sorrow. Darkness is an expressive type of sorrow. The mind that knows not God, knows not the heart’s best rest. There is no solace for our griefs like the gospel of Jesus Christ, and those who are ignorant of it are tossed about upon a stormy sea, without an anchorage. Glory be to God; when sorrow has brought on a midnight, grace can transform it into noon. ~ C.H. Spurgeon
https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1010.cfm