I think it may have been St. Augustine who said in essence, as an unbeliever you do not believe God exists; as a believer I believe He does exist and everything He says is Truth. What if when you die I am right and you are wrong? It will make a tremendous difference to you in the way you lived your life. You will face judgment and sentencing from the God of the Universe. If when I die and you are right, it won't really make any difference to me, I will be dead. How willing are you to take that chance?
Going a step further, when a person believes in God, how is it not possible to also believe He has tirelessly communicated with us to reveal His plan of salvation? If a person believes in God and even believes on a cursory level the writings in the Bible, how would it be possible not to believe that God worked through His Son Jesus to reconcile the world to Himself through the sacrifice of shedding His blood on the cross to provide the means for salvation to all who believe?
To stand firm in disbelief in the face of all evidence God has offered is a stubbornness rooted in ignorance, grown into foolishness and finished in futility.