Those who are perishing can repent, in which case they will bring for the fruit of repentance, or they can stick to their guns till the end, in which case we should not expect them to have a high opinion of sound doctrine.
We are not called to be considered of good repute to the lost, we are called to speak the word both in and out of season.
Guess what: to those “out of season” they are likely to resent God’s word.
And that’s THEIR problem.
So do you believe that Adolf Hitler could be in Heaven after repenting? Josef Stalin? Mao?
If there are other gracious answers we can be giving and we won’t — then it’s our problem again.