True faith is not blind. It accepts trustworthy testimony, as everyone does every day when they read, listen or watch.
With respect to the true Christian’s faith, it then goes on and has one or more personal experiences that the individual cannot deny, and they will thus not deny their Lord, even on pain of death. It may be ‘only’ the recognition of his sacrifice and personal love for them – not to diminish the miraculous work of the Holy Spirit in a life, as he did in the repentant thief on the cross – and that heart and mind have been irrevocably changed, loving Jesus and God. Or, it may be something empirical as in George Müller’s amazing example, or Maggie’s (for a shorter read), demonstrating one M.O. that God frequently uses. Others like yourself may deny that there is any meaning imputed by the event(s) or that the omnipotent, sovereign and personal God even can act interventionally into his children’s lives in his providence, but that is no matter.