"Unshakable conviction" refers to a strong belief or confidence in something that cannot be easily changed or influenced by others. It means having a firm and unwavering belief, regardless of any challenges or doubts that may arise. Full definition
If he has seen almost unbelievable courage and endurance and, what is even more moving, an unshakable conviction of the final goodness of God, he is bound to feel humble. (religion-online.org)
Yet it remains the unshakable conviction of Christians, from New Testament days until today, that there is what must be called, for want of a better word, an «eternal» order, an «eternal» plan and an «eternal» life. (religion-online.org)
They were sporadic, elusive, evanescent, yet leaving in the minds of those to whom they happened an unshakable conviction that they had indeed, for a short space of time, been in the direct presence of their living Lord. (religion-online.org)