I don't think that those of us who have already accepted the Truth should feel obliged to get involved in the kind of polemical agenda to "prove" our salvation in a legalistic manner as others do.
The Apostle says "But they didn't all listen to the glad news. For Isaiah says, "Lord, who has believed our report?" So faith comes by hearing, and hearing by the word of God." And our Lord, who gave himself up to the enemies of the Gospel to be crucified said "Most certainly, I tell you, the hour comes, and now is, when the dead will hear the Son of God's voice; and those who hear will live." And again - Pilate therefore said to him, "Are you a king then?" Jesus answered, "You say that I am a king. For this reason I have been born, and for this reason I have come into the world, that I should testify to the truth. Everyone who is of the truth listens to my voice."
Many times Christ says "he who has ears to hear let him hear", but who does not have ears to hear (excepting that some may say deaf people)? Furthermore he says "seeing they do not see and hearing they do not hear, nor do they understand" showing this to be a wilful ignorance of the part of those rejecting the Gospel. So it comes to whether we believe the words of our Christ, the Savior and King, and the testimonies of the first Christians about him, which we clearly do. "He who believes and is baptized will be saved; but he who disbelieves will be condemned." (Mk. 16:16)
"He who believes in him is not judged. He who doesn’t believe has been judged already, because he has not believed in the name of the one and only Son of God. This is the judgment, that the light has come into the world, and men loved the darkness rather than the light; for their works were evil. For everyone who does evil hates the light, and doesn’t come to the light, lest his works would be exposed. But he who does the truth comes to the light, that his works may be revealed, that they have been done in God.” (Jon. 18:21)
Those people who produce only aversions of various kinds to reject the Gospel show unceasingly they have long rejected the Truth and all we can do is pray that may be given eyes to see and ears to hear, and a heart of understanding. Amen.