The Bible is full of evidence of Jesus' death for us.
You have trouble understanding the word evidence. It has stories but no evidence. In order to be evidence something else must corroborate it. Nothing else corroborates the bible, all other "evidence" is derived from the bible. There is no "evidence" independent of the bible.
No, it is you who have a problem with the concept of evidence. The Bible is a collection of the writings of independent witnesses, it needs no outside corroboration.
It's matters not to me what people believe privately, but when they publicly offer their unevidenced rationales they shouldn't expect others to respond, "Oh, that makes perfect sense." If it makes sense to you that's all you should require.
I just gave you a ton of evidence, and if you haven't tried to understand it how do you know if it makes sense or not? However, you are not, of course, obliged to consider it if you don't want to.
But you nevertheless feel free to oblige me to require no more than it make sense to me? Where do you get the authority to tell me I should be content with what makes sense to me and not try to persuade others of these things?
How this can be dismissed as Apologetics is beyond me.
To prove the Trinity takes a long list of Biblical verses. I did at least sketch out in that one post I linked to what the categories of those verses are. Individual verses show that God is One, that the Father has the attributes of God, that the Son has the attributes of God, and that the Holy Spirit has the attributes of God, and they show the three acting independently of one another as separate "Persons." When the subject first came up it was understood that I couldn't spell all that out without taking up too much space and that simply indicating what the link explained was sufficient in this case. However, I'll try to get back later and find at least one verse per category to make the point.
The evidence is in the list of verses, but there was some sort of preamble to the list explaining that the Trinity isn't stated in so many words but inferred from all those separate verses that present the nature of God as One in Three independent Persons, then the verses show that to be the case.
I don't know why I wrote that the way I did; I agree it doesn't make sense as written. But I'd respond now that you can't compare the Bible, which is many books written by many authors over millennia, to any work of fiction. To derive a complex concept like the Trinity from all those different books does require something supernatural about those books, something the authors themselves weren't even conscious of.
And when somebody doesn't even try to understand the Trinity it's awfully hard to discuss it, as you do here:
You say God is a threesome: God, Jesus and the Holy Ghost.
But that is not what the Trinity is and not what I've said. You make one of the typical mistakes about it when you confuse God the Father with the Trinity itself. The three are God the Father, God the Son and God the Holy Ghost; all three make up God the Trinity, One God in Three Persons. Occasionally God the Father represents the Trinity in scripture, but you have to understand the concept to know how to read these things.
We are to understand the Bible by the light of the Bible. Many heresies are the result of taking a concept out of context. When you find a statement that treats God the Father as representative of the Trinity, you can easily misunderstand it unless you know what the Bible says overall about the Trinity.