Identity: "the Zealot" or "the Cananaean"
Simon appears in all four apostolic lists, distinguished from Simon Peter by the title "the Zealot" (Luke 6:15; Acts 1:13) or "the Cananaean"/"Canaanite" (Matthew 10:4; Mark 3:18) — not a reference to Canaan or a place called Cana, but a Greek transliteration of the Aramaic qanai, meaning "zealous one," essentially a synonym for "Zealot" in Greek versus Aramaic form. This designation most likely identifies Simon with the Zealots, a Jewish nationalist movement committed to armed resistance against Roman occupation and opposed to any compromise with Gentile rule — the same movement that would later drive the catastrophic Jewish revolt of AD 66–73. If this identification is correct, Simon's presence among the Twelve alongside Matthew, a former Roman tax collector, represents a genuinely striking juxtaposition: a man committed to violent revolution against Rome, and a man who had literally profited by working for Rome's occupation apparatus, both called into the same intimate group of twelve by Jesus, evidence of just how thoroughly Jesus's movement cut across the era's sharpest political and social divisions rather than aligning with any one faction.
Later mission and martyrdom tradition
Simon receives no individual narrative anywhere in the Gospels or Acts beyond his name appearing in the apostolic lists — among the least individually documented of the Twelve. Later tradition, again drawn mostly from the largely legendary sixth-century Acts of Simon and Jude, holds that he preached first in Egypt before joining Jude (Thaddeus) in Persia, where the two evangelized together, confronted opposing pagan priests, and were ultimately martyred for their refusal to sacrifice to idols. Simon's traditional manner of death — being sawn in half — became his standard iconographic symbol (he's typically depicted holding a saw in religious art), though this detail, like many apostolic martyrdom traditions, appears relatively late and is not attested in the earliest sources. Notably, the fourth-century theologian Basil the Great records an alternative, considerably less dramatic tradition: that Simon died peacefully in Edessa rather than by violent martyrdom in Persia — a reminder that even among traditions this old, real disagreement about basic facts survived into the patristic period itself.
Why it matters
Whatever the precise details of his later life, Simon's likely background as a former Zealot sitting at the same table as a former tax collector is worth sitting with as one of the New Testament's clearest quiet demonstrations that the kingdom Jesus proclaimed didn't ask people to first resolve their political differences before belonging to it together — a detail with obvious, direct relevance to any context where political and tribal loyalties run deep and Christian unity is asked to cut across them rather than simply mirror them.