I want to tell you about an exchange that took place between the angry atheist's mum and me before the angry atheist joined the conversation.
She had told me that she was a militant atheist, and when I asked why, she told me it was because she had examined the whole thing and there wasn't a shred of evidence for it. Now when you hear that kind of language you know you're talking to a bluffer - of course there's evidence for God and Christianity - I have a whole shelf of it! Someone may not find it compelling or convincing, they may think it's poor evidence, but it's still evidence.
Anyway, I asked her if she was familiar with Isaiah 53 and Psalm 22. She (quite understandably) wasn't able to recall what those passages spoke about, so I read them to her and asked her if the descriptions reminded her of anyone. She said they sounded like Jesus. I asked her how, as an atheist, she could explain that, given these passages were written hundreds of years before the birth of Christ. She said that the Romans were crucifying people left, right and centre back then. I pointed out that the Roman Empire was not in existence back then, and neither was crucifixion.
She asked to see the passages again, and she said with triumph, It doesn't say "They pierced my hands and feet to a cross"! It just says "They pierced my hands and my feet"! She said that could be talking about anything (albeit it initially seemed pretty clear to her that it was speaking about crucifixion). I'll admit, I found this to be a very weak response, and told her so. I tried to point out that because the accounts don't contain every detail of His death, that doesn't explain away the detail it does contain.
Take an illustration I have used before about a man going to get petrol. Imagine I told you that tomorrow at 9.02am a man would come to a certain petrol station to get petrol. Imagine I told you the type and registration of the car he drove, the name, height, age and address of the man, and a description of what he would be wearing. Imagine all the events came true and you were standing watching this, and you said to your friend, "Wow, that all matches what Paul said would happen, how do you explain that?" Would it be an adequate response if your friend snorted and said, "That doesn't need an explanation, because Paul never said how much petrol the man would put in his tank, and he didn't say what aftershave the man would be wearing - so think no more about it!" Of course it wouldn't! That isn't a satisfactory explanation. The details that weren't included in the prediction don't make the details that were included disappear!
What we have in Psalm 22 is a vivid description of someone suffering at the hands of Jewish (the bulls of Bashan is Old Testament imagery of Israelite oppressors, the bulls being strong animals and ceremonially clean, see Amos 4 v 1) and Gentile authorities (the Gentiles were called dogs by the Jews), exposed to physical exhaustion and intense heat, being stripped, mocked and stared at, having pierced hands and feet, and dislocated bones, and entering into darkness and death. If that doesn't describe the crucifixion then I don't know what does.
If that lady is satisfied that her rejoinder explains away Psalm 22 and Isaiah 53 then it is a testimony to the tenacity of her commitment to atheism. If I were an atheist Psalm 22 and Isaiah 53 (among many other prophecies) would really bother me, and her "answer" would do nothing to allay my doubts or calm my fears.
Those passages not only show us the reality of the Gospel, but the relevance of the Gospel, because they tell us not only that Christ would suffer, but why - He suffered for us so that we can be saved. Read them for yourself.