Even if the shroud was the burial cloth of Christ, even if certified dead people came back to life speaking of the horrors of hell; if stubborn sin ridden folk don’t want to submit to God then they’ll come up with any excuse not to do so!
If they don’t accept the testimony of even Thomas, will they even accept the shroud without doubt?
Reminds me of Lazarus and the rich man, ...
(27) Then he said, I pray thee therefore, father, that thou wouldest send him to my father’s house:
(28) For I have five brethren; that he may testify unto them, lest they also come into this place of torment.
(29) Abraham saith unto him, They have Moses and the prophets; let them hear them.
(30) And he said, Nay, father Abraham: but if one went unto them from the dead, they will repent.
(31) And he said unto him, If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.
On the other hand, even in the Shroud, the Gospel is made manifest and may be used as a reference in communicating the Word of God.
Yes, true. But it can be a nice booster for some who need it in their doubts.