English “saint” comes through Latin sānctus (“holy, consecrated”), the past participle of sancīre (“to consecrate, make sacred, render inviolable”). That verb traces to PIE *seh₂k- / *sak-, “to sanctify, make a treaty sacred” — the same root behind Latin sacer (“sacred”) and sanciō. So saint’s lineage is PIE *sak- → Latin sānctus → Old French saint → English.
Punjabi/Sanskrit “sant” (संत / ਸੰਤ) comes from Sanskrit sant-, the present participle of as- “to be” — literally “being, existing, real, true,” and by extension “good, virtuous, a good/realized person.” The root is PIE *h₁es-, “to be” — the same root that gives English is, Latin est, Sanskrit asti. The feminine satī (“a true/virtuous woman,” source of the English word suttee) and the abstract satya (“truth”) are from the same family. So sant’s lineage is PIE *h₁es- → Sanskrit sat-/sant- → Punjabi sant.
The Latin word builds holiness out of consecration — something made sacred by ritual act, set apart, inviolable. The Indic word builds it out of being — the one who truly is, the real/authentic one, holiness as ontological truth rather than ritual setting-apart.