Just trying to present a relaxed discussion.
Ok.
Just as you think others are adding when they want to be water baptized, to me, you are also adding to the gospel when you are claiming 1 Corinthians 15:1-4 is not sufficient to save anyone.
Firstly, I did not say that 1 Cor 15:1-4 is not sufficient to save anyone. I said that it doesn't contain the whole Gospel - it doesn't mention the Holy Spirit. It also doesn't mention that Jesus was/is God.
Now when Paul wrote it, I have no doubt that he had explained these things to the Corinthians and told them exactly who Jesus was. He had also, previously in the letter, taught about the resurrection and the Holy Spirit - seeing as they were able to speak in tongues (chapter 14.)
But the point I was trying to make was that if you said to a non Christian today "believe that Christ died for your sins, that he was buried and that he was raised", you would probably be met with blank looks. Even if the non Christian had a church background, you might still need to explain those verses - in my experience, for example, if people live "good" lives and occasionally go to church, they don't believe they are sinners. If the non Christian you are speaking to does not have a church background, you would need to explain who Jesus was - not just a good man - what it means that he died for our sins and so on. There are hundreds of books, booklets, tracts and teaching courses on how to present the Gospel; none of which say, "just quote these 4 verses in 1 Cor and that's all that's needed."
I am not adding to anything.
I am saying that presenting/proclaiming the Gospel involves more that saying "believe Christ died for your sins was buried and was raised." Even Paul says this. He taught, elsewhere, about Jesus being the second Adam, about us dying to sin, about being reconciled to God, about living life in the Spirit (Romans 8), about God's love, spiritual warfare and Jesus' return. All of that is found in Paul's 13 letters, yet he doesn't mention it in 1 Cor 15:1-4.
Of course these verses COULD save - God can do anything and doesn't even need our help, or input, to do so. But if you went up to an unbeliever, quoted these verses and the unbeliever immediately believed, that would be because the Holy Spirit was, and had been, working in them. Yet the Spirit himself is not taught in these verses.
Secondly, I don't remember, originally, mentioning water baptism at all - so, if anything, you have added that to our discussion.