Understanding the Symbol of Salt and Light in Context

Salt and Light in the Old Testament

In the Old Testament, salt and light symbolize God’s covenantal faithfulness and the presence of His holiness.

Salt is first linked to covenant permanence in Leviticus 2:13, where it is required for grain offerings, signifying the enduring nature of God’s promises. Light, meanwhile, is associated with divine guidance and presence, as seen in Exodus 25:37, where the lampstand in the Tabernacle was to burn continually, representing God’s unceasing revelation to His people. These elements thus anchor the biblical narrative in themes of stability and illumination.

These symbols prefigure New Testament teachings by framing Israel’s identity as a covenant community called to reflect God’s character. Their ritual roles in the Old Testament underscore how salt and light later become metaphors for the church’s mission to preserve and proclaim truth.

Jesus as the Source of Salt and Light

In the Sermon on the Mount, Jesus redefines salt and light as metaphors for his followers’ ethical and missional role, building on their covenantal significance in the Old Testament.

Matthew 5:13-14 declares that believers are 'the salt of the earth' and 'the light of the world,' emphasizing their responsibility to preserve moral integrity and radiate God’s truth. Salt, which preserves and enhances flavor, symbolizes the transformative power of a holy community in a corrupt world, while light, visible on a hill, represents the public witness of God’s people. Jesus’ imagery draws from Mark 9:50, where salt must retain its saltiness to be useful, and Luke 14:34-35, which warns that useless salt is discarded. These parallels stress that discipleship demands active engagement, not passive existence.

The ethical and missional identity of Jesus’ followers hinges on their connection to Him as the ultimate source of salt and light. Jesus is called 'the light of the world' in John 8:12. His disciples reflect his character through their deeds and testimony.

This redefinition shifts the focus from ritual purity to lived holiness, calling believers to embody God’s covenantal faithfulness in a way that impacts both community and culture. The imagery also carries a warning: without Christ, even the most outwardly pious life risks becoming inert or hidden. The next section will explore how this identity shapes the church’s mission in the world.

Living as Salt and Light Today

Jesus' call to be 'salt and light' challenges believers to live with ethical courage and visible faith in a world marked by moral ambiguity and spiritual retreat.

Ethical integrity, like salt preserving food, means standing for truth in a morally relativistic culture (Matthew 5:13), while public witness, like light on a hill, demands active engagement rather than private faith (Matthew 5:14). Neglecting these roles risks inertness - losing one’s distinctiveness (Mark 9:50) - or irrelevance, becoming 'good for nothing' (Luke 14:34-35). cultural relativism undermines salt’s preservative role by adapting to shifting values, and spiritual privatism hides light beneath a bushel, contradicting Jesus’ command to let it shine (Matthew 5:15). By embracing these symbols, believers become counter-cultural agents of preservation and illumination, reflecting God’s covenantal faithfulness in a fractured world.

Going Deeper

To deepen our understanding of salt and light, consider their connection to law and grace in Matthew 5, the theological use of metaphor, and insights from historical figures like Augustine and Luther.

Matthew 5:17-19 reveals Jesus fulfilling the law’s demands while calling for a transformed heart, paralleling how salt and light preserve and reveal God’s kingdom. Augustine interpreted salt as the church’s role in preserving moral order, while Luther saw light as Christ’s unmerited gift, not human achievement.