When did the Trinitarian concept enter and disrupt the strict monotheistic religion of Judaism and early Christianity?

I am not subscribing to no other God but one.

He was talking to them (Angels not other Gods) but they didn't help in creation, God alone did that.

I am "only making this post" to prove what the Hebrews factually believed between a triune God or a singular God.



** I went to synagogue from ages 6 to 13 and never heard any Rabbi refer to a triune view for the Torah or Tanakh. The Talmud to the Torah/Tanakh is basically the same as the Strong's Concordance to the KJV Bible.**

1)
This is what the Talmud (Concordance) of the Hebrew Old Testament claims about Genesis 1:26.

Talmud/Hebrew explanation:
A)
The tractate Megillah58 and the minor tractate of the Babylonian Talmud called Sofrim59 implied that in Genesis 1:26 (let us make) should be interpreted that God was the sole Maker [I will make].

** I have never met a single Rabbi or read any notes going as far back to the Talmud (500 B.C.) that shows any Hebrew believed the Torah/Tanakh implied a trinity. **

2)
Even in the case of Isaiah 48:16 Come ye near unto Me, hear ye this: From the beginning I have not spoken in secret; from the time that it was, there am I; and now the Lord GOD hath sent me, and His spirit.

Hebrew explanation:
A)
The last two Hebrew words in this verse are shelachani ve-rucho ("He has sent me, and His spirit"), with "me, and His spirit" being the direct objects of "sent."

3) the meaning of the word Elohim.

Hebrew explanation:
A)
Elohim is one of the Hebrew words for God, usually referring to the one God of the monotheistic religion of the Israelites described in the Hebrew Bible.
B)
Elohim, when meaning the God of Israel, is grammatically singular, and is commonly translated as "God", and capitalized.



** So there's no Hebrew writing that indicates they believed in a triune God. This is a myth created by modern Christian opinion. **

Do you mean to say they expected God to incarnate as Jesus did?

Because the religious leaders and teachers of Jesus's day, the scribes and Pharisees, and even many
of the people, strenuously objected to Jesus making any reference to His equal status with God.
As proven by their desire to stone Him to death for blasphemy...

The bible is crystal clear Jesus is fully God
Same goes for the Father
Same goes for the Holy Spirit.

Jesus could forgive sin of those who hadn't directly offended Him personally. A normal person can say I forgive you to someone who hasn't offended them..but it means nothing. Jesus saying it..means He actually can forgive sin of anyone.

When Jesus was saying He was doing things 'by the Father's hand' etc.. to the Jews..this is saying 'I am equal with the Father ' . Because that is how Jews understood agency. The agent carrying another's message has the same authority. The message becomes the agent's own.

The New Testament is clear about your post, not the Old Testament.

Well let's start with this:

Jesus talking about the Old Testament (this is what the scriptures were usually when Jesus talked about them)..

John 5:39 KJV - Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me.

When did the Trinitarian concept entered Christianity?

Exactly at the baptism of Jesus Christ.

Matthew 3:13-17

Yeah, He also said Moses and Prophets spoke about Him. So the Old Testament references to God, Jesus is saying was Him.

That can also be used for the "sign" John the Baptist was given to know who the Messiah was.

33 I myself did not know him, but he who sent me to baptize with water said to me, ‘He on whom you see the Spirit descend and remain, this is he who baptizes with the Holy Spirit'

We see that in Mathew 3: 13-17 Jesus convinced John to baptize him and John said Yes, without seeing a miracle.
But let's disregard this detail because it's something we are allowed to do in Christian discussions.
Let's look at this from another point of view.

We could reasonably say that there were hundreds of other people at the time because "all the country of Judea and all Jerusalem were going out to him and were being baptized by him in the river Jordan, confessing their sins” (Mark 1:5)

So, when people see Jesus Christ, see a Dove descending and hear a voice that says "This is my Son", it's not evidence enough for you for the Trinity and for the When?

Well, the OP wants a technical answer so give him a technical answer.
He wants to know the when.
He wants to know the time zone, date, year, hour, the lunar cycle and other details.

The baptism is exactly When.

It happened before Jesus chose the Disciples so we only really see that John saw it.

Ah okay, so this is the second time we disregard some other details in discussion like other people being present when John was baptizing as mentioned on Mark 1-5 or that John's disciples might have been present there.
So i guess you don't know when, then. It's a mystery.

Other people being present doesn't mean they saw the "sign" that was only for John.

I looked up search for who all saw this phenom and unanimously scholars all claim only John the Baptist.

Well, if i ask people or priests in the Orthodox Church for example they say that other people could have been present.
So what can we conclude from this?

1. It's possible you can never know the when, and the question in the OP has no meaning.
2. It's possible that we ignore certain chronological events like when Jesus convinced John to baptize Him without a miracle occurring ...yet.
3. It's possible that this is another case of "But this [action] is not in the Bible" despite the Bible saying some chronological events.
4. It's also possible that people might reject certain things even if they're spelled out correctly in the Bible.

So, the When remains a mystery then.

We don't need to. Over 2000 years of church history supports Trinity doctrine. The onus is on you to prove otherwise, and you haven't.

I am not saying other people were not there present.
I am saying this "sign" was only for John and not other people.
So John saw but other people did not see.