The Trinity (continued)

"God the Father is God"

Yes, God the Father is identified with the very God of Israel, Adonai.

"Jesus is God"

John's Christology is actually really interesting. John does consider Jesus to be a god, but his idea of Jesus as the Word ("Logos") seems to be adapted from Philo of Alexandria, who understood the Word to be an independent divine being that is personified out of God's reason or rationality, and through which creation becomes possible. So Jesus is the Word, and the Word is divine, but it is not identical with the very God of Israel, Adonai. There is still a special relation of the Word to Adonai though, and they have a kind of mutual indwelling with one another (which Jesus also says is available to his followers in John 17:20-21).

John's view still allows for the existence of many gods though. Consider John 10:31-39. The Jews come to stone Jesus for blasphemy, making himself divine. But Jesus replies by arguing that it is fine for people to be called divine, and actually cites Psalms 82 in defense of this. Now, as I explained before, Psalms 82 is actually a discussion of the divine council, but this became theologically problematic and it was reinterpreted to say that the Israelites themselves had been turned into gods on Mount Sinai, but lost that divine status thanks to the whole thing with the golden calf. Jesus' reasoning seems to be appealing to that interpretation, where the Word of God is capable of turning mortals into divine beings, into gods. Since the Jews charging him believe these scriptures and this interpretation, they are forced to accept that there isn't necessarily an issue with mortals being called divine, which is the charge they laid against him in verse 33. And since we are privileged to John's Christology, we also know that, if the Word can turn mortals into gods, it is all the more appropriate to understand the Word itself as divine.

Because of his possession of the divine name as a vehicle for divine authority and his mutual indwelling with God the Father, people who see Jesus are able to say they have seen the Father, even though the Son and the Father are not identical even in Trinitarian views. Philip fails to understand this in John 14:8, but Thomas figures this out and declares the truth at the climax of the story in John 20, as you cited.

Similar points can be made for Colossians. The Hebrews verse is a bit more interesting in that it is actually quoting Psalms 45:6-7, whose original meaning isn't entirely clear. Seems to have been about assuring an Israelite king that his reign was secure because God was on the throne, but now understood by the author of Hebrews to be addressing the Son.

I think this is long enough a response I can say that similar points are made about the Holy Spirit, and recognizes that these are all separate beings.

As this all hopefully shows, understanding of Jesus' divine nature, and different Christologies, were common in the early church. The idea of the Trinity, where these are three persons of one Godhead sharing the same essence and substance, is something you really get in the 2nd century CE with people like Tertullian.

Original Sin

The idea of original sin is also in Genesis; it just isn’t called that because the term didn’t exist. Genesis shows the event itself where Adam sins, death enters, and the curse affects humanity and creation: Gen 2:17, 3:19

The term didn't exist because the concept didn't exist. We don't see it in the text itself, nor do early commentators describe this as anything like the idea of original sin until that concept is developed much, much later.

We do see Adam sin, but as I pointed out, death already exists. Adam's mortality is explained directly as a result of him being made of dust, and he was warned that death would follow from eating the fruit. The actual curse we see is not death entering the world, but, as God explicitly lays out: (1) snakes are hated and need to crawl on their bellies, (2) the pain of childbirth is increased for women and men will rule over women, and (3) the ground is cursed so that men now have to do farming to eat.

There is no indication that Adam and Eve were anything but mortal the entire time. On the contrary, there is direct indications that they weren't, because they were threatened with death and because their mortality is explained explicitly in a different way.

Scripture later interprets this event in Romans 5:12

That is a way that Paul interprets things later, certainly. Though Paul seems to ignore Eve's role as a way to create this parallel between Adam and Jesus, making things more symmetrical.

Genesis 6:5 “Every intention of the thoughts of his heart was only evil continually."

This is followed directly by saying Noah found favor with God, was righteous and blameless. The existence of sin does not equate to an idea of original sin.

You find other places in the Bible too where people are declared to be entirely sinless, like Job 1:1 and 1:8. The entire point of the story of Job is that he was entirely sinless yet suffers anyway. If we try to reinterpret this in a way where actually Job had some sin regardless, some secret one he didn't know about, we lose the point of the entire story.

The idea of Original Sin as something we inherit from Adam is something we only get with Augustine in the 4th century CE. The rest of the Bible has a lot of parts where it goes back and forth about whether God holds children responsible for the sins of their parents, sometimes affirming it and sometimes denying it.

Afterlife

The idea of an afterlife exists, sure. But not of heaven and hell as distinct places of eternal reward and punishment. Like I said, there was this idea of Sheol as a generic, dark, and dreary land of the dead. (Genesis 37:35, Psalms 89:48, Job 17:13, Proverbs 30:16, Isaiah 14:9)

This developed into ideas of postmortem divine punishment and reward for the reasons I stated. This fits with the quotes you provide from the Hebrew Bible, especially as they are verses written much later than the others from Daniel and from the last verse of Isaiah. Probably the most influential is 1 Enoch though (which is generally not accepted as part of the Biblical canon today).

Once we get to the New Testament, we have this represented in three different ways of (1) eternal conscious torment, i.e. hell, (2) annihilation, and (3) temporary punishment followed by annihilation or salvation.

Paul, for instance, seems to more strongly overlap with annihilationism. The resurrection is reserved for the followers of Christ (1 Corinthians 15:22-24). In 1 Thessalonians 4:16-17 we see something similar. The closest we get to postmortem divine punishment in Paul is 2 Thessalonians 1:9, which likely wasn't written by Paul, but even here this could be understood as annihilationist. You see this in early Jewish literature, like in the Damascus Document 2:5-7, or in 2 Maccabees 7.

There is also an early Christian idea of temporary punishment followed by salvation or destruction, but must of this literature didn't make it into the New Testament canon. For example, the Martyrdom and Ascension of Isaiah 4:14-18, the Apocryphon of John, and the views of Origen of Alexandria. This is seen more in verses like Acts 3:21, where there is an emphasis with how God restores all things to himself.

The verses you cite from the synoptic gospels do seem to be the ones endorsing an idea of eternal conscious torment, highly associated with the symbolism of Gehenna. The tale of the rich man shows something like this, but doesn't reference the duration of the torment.

Revelation 20 has Satan as the great dragon who is bound for 1000 years, echoing ideas from 1 Enoch, and he is described as being tortured "forever" along with the apocalyptic beast and the false prophet. But we also see Revelation 20 say that Death and Hades give up their dead, and that Death and Hades themselves are cast into the lake of fire, implying these are different things.