Am I being a heretic?

Did the angels know God was triune before He said this?

I don't think Lucifer did, yet. Or would he have attempted to temp Jesus?

No doubt you needed it if not it' ll do for next time

I believe so although I would not mind if it is not true.

The creation was formed with God’s estate already established among the Father, Son, and Holy Spirit. All of creation is framed by their relationship. But, their relationship is never examined outside of creation. God simply was. The reason He is there in three parts is to show us our place in the Son at the beginning of time. Because of this we are assured of our reconciliation back to the Father.

Before time, the spiritual was first and the natural followed. Now, in time and space, the natural shows the spiritual. At the end, God will be all in all when the Son puts everything under the feet of the Father. I believe this is the “natural” state of of the Living God.

Well, knowing God is triune isn't exactly the same as knowing Christ is God. But I agree I don't think Satan knew who Jesus is until at least the end of testing Him, when the Lord dismissed him, and he was compelled to leave. But I suspect it even until Gethsemane.

But it's interesting, perhaps God said 'let Us make man.. " in heaven, and it wasn't heard by Satan if he was already cast down.

I think the rebellious saw they’re opportunity to usurp God because He appeared as the Son.

They had no chance vs. God as God. But Goad as Son, who came in the form of man… they saw their chance. Had they succeeded, they would have proven God could not protect His own estate.

the scripture is explicit that "in the form of man" doesn't mean full of sin.
God cannot be tempted: each man is tempted when he is drawn away by his own lust - but in Christ is no sin: He could not be tempted. He was tested in every way we are, yet without sin. it is impossible that Jesus was tempted in any way -- but tested.

so they could only have thought as you say they thought, if they did not know who He is. if they had understood, they would not have tried to tempt Him -- trying to tempt Him is evidence of ignorance of Him. thinking Christ can be tempted is evidence of ignorance about Christ.

We really have no way to know what happened before Genesis 1:1 as it was never written, there's nowhere to start.

Not necessarily. Satan is hubris personified, among other things. Even so, in His flesh He was “a little lower than the angels”.

meant this for posthuman .It is written he was tempted in all ways yet without sin.

Heb 4:15
For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin.

the word is "tested"

God cannot be tempted. ((James 1:13))
every man is tempted when he is drawn away by his own wicked desire. ((James 1:14))

if you have Christ being "tempted" then you have Him full of wicked desire - so you have Him full of sin in His heart, which He Himself says is just as sinful as if one expresses that sin ((Matthew 5)).
so if you have Jesus being tempted then you have Jesus a sinner, and then you do not have a spotless lamb so He is not an acceptable propitiation and you have declared that there is no Salvation.

Christ was tested in every way yet without sin.

Isaiah 14:13 “You said in your heart:
“I will ascend to the heavens;
I will raise my throne
above the stars of God.”

This is the heart of Satan: to exalt himself above God. This would effectively overthrow Him.

Satan is not greater than Christ. Satan, however, was greater than Jesus, in terms of personal power. Jesus, in the flesh, could be tempted.

“For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin.”

Temptation does not require wicked desires. It only requires the weakness of the flesh, e.g. hunger, fatigue, etc.

James tells us how "temptation" works. the sin in a persons heart is aroused and draws us away.
so do you believe Jesus had a heart full of sin? or do you agree Christ is without sin?
do you agree with Christ who said sin in our hearts makes us just as guilty as if we carry out that sin with our hands?

Jesus was tested in every way, yet without sin and that same Jesus teaches us that sin in our heart is every bit as condemning as sin that is expressed.

is Jesus condemned?

This in my view is heresy, or borderline heresy. God is and always will be separate from His Creation. The Word became flesh - Christ Jesus became a man - but He did not create Himself. While your belief may be accurate, your words are not, and in my view, should not be used as such to describe the Trinity. I defer to using the words of scripture to avoid error when trying to explain this difficult-to-understand truth.

I mean, if you make yourself like the Most High, then you have no equal. There is only one “most”. By this, Satan wants to usurp God.

Jesus was not the son of Adam, He was the son of God. He did not inherit Adam’s heart, but the heart of His Father in heaven. He was God in the flesh. That’s not a title, that’s a reality: He was God in the body of a man. His body had all the weaknesses of man (and weakness is not sin) but He never acted on His own to assuage those weaknesses. This showed that in every way He was able to resist the devil in spite of the weakness of the flesh. Without the weakness of the flesh He could not be the pattern Son of God For us. He would present an impossible standard.

Furthermore, all angels are servants. God’s estate, with man as His heirs, was established before creation began. The angels were formed to serve the House of God, they knew what He place was established for man before man was created. This is elementary.

postman you didn't think this through one could be tempted by chocolate cake... God the father cannot b tempted. but Jesus was a man in every way yet without sin.