You asked

what understanding of light, darkness, and the eye would jesus's original audience have had?

Adds the setting and its conversation across both testaments.

Matthew 6:22-23

““The lamp of the body is the eye. If therefore your eye is sound, your whole body will be full of light. But if your eye is evil, your whole body will be full of darkness. If therefore the light that is in you is darkness, how great is the darkness!””

This passage comes from Jesus's Sermon on the Mount, a collection of his teachings to his disciples and a larger crowd. Here, Jesus speaks metaphorically about the eye's role in determining one's inner state and perception of the world, placing it within a larger discourse about true treasure and allegiance.

What does it mean for the 'light that is in you' to become darkness?

Then — the setting

Jesus's audience in 1st-century Galilee would have understood 'light' and 'darkness' not just physically, but also as powerful metaphors for good and evil, truth and falsehood, knowledge and ignorance. The 'eye' was seen as the gateway for perception and understanding, often also linked to generosity or envy. A 'sound' or 'generous' eye (as 'haplous' can imply simplicity and generosity) would lead to clear moral vision, while an 'evil' or 'stingy' eye ('poneros') was associated with greed, envy, and a distorted view of the world. This wasn't a scientific statement about optics but a moral and spiritual one about how one perceives and interacts with reality.

Across the Testaments

In the Old Testament, light and darkness are fundamental elements of creation (Genesis 1) and frequently symbolize God's presence, guidance, and truth (Psalm 119:105) versus chaos, evil, and judgment (Isaiah 5:20). The eye, similarly, is often portrayed as the organ of perception, both physical and spiritual, with 'seeing' often meaning 'understanding' or 'believing.' Jesus's teaching in Matthew draws deeply from this established symbolic language, re-framing the internal moral state as the determinant of whether one's whole being is filled with 'light' (God's truth) or 'darkness' (moral corruption), echoing themes found in wisdom literature like Proverbs.

Keep thinking

Read alongside it

Luke 11:34-36
A parallel teaching from Jesus that further elaborates on the eye as the body's lamp.
Proverbs 28:22
An Old Testament proverb connecting an 'evil eye' to a desire for wealth, reflecting a similar moral understanding.
John 3:19-21
Jesus connects light and darkness with actions and moral choices, highlighting a spiritual dimension.

Ask your own follow-up