Short answer: In Jainism, Tirthankars do not “bless” or change anyone’s karma by will.

Why?

• Tirthankars are Vitarag — completely free from attachment and aversion. They neither grant boons nor punish. Their role is to show the path, not to interfere in the law of karma.
• Results come from our own karmas. Jain Dharma teaches a strict, automatic law of karma; no divine favoritism.

Then why do we pray and do puja?

• We worship their supreme virtues. This creates auspicious feelings (shubha bhav), reduces passions, and earns punya. That inner purification becomes the cause for relief from obstacles and spiritual progress. In simple words: their “grace” is their teaching; the benefit arises from our purified effort in their refuge.
• Navkar Mantra says this reverence is the foremost mangal and “destroys sins” — meaning it destroys sinful tendencies by cultivating humility, right faith, and restraint.

Digambar and Shwetambar view

• Both traditions agree: Tirthankars do not give worldly favors or change karma. Differences are only in some ritual forms, not in this core principle.

Helpful references

• Meaning and purpose of Navkar Mantra:
• Benefits of Navkar/why we pray (focus on inner purification and punya):
• Prayer and dhyan in Jain philosophy (self-effort over miracles):