"I will declare the Lord’s decree: He said to Me, “You are My Son; today I have become Your Father." Psalm 2:7
But Who is that Son, exactly?
All we need to do is go up a few verses to see Who is being spoken about.
2 "The kings of the earth take their stand, and the rulers conspire together against the Lord and His Anointed One:"
Do you know what the term "Anointed One" translates into in Greek?
I'll give you a hint. Here is the Orthodox Jewish Bible translation's rendition of the same verse (caps mine):
2 "The Malchei Eretz rise up in rebellion, and the rulers take counsel together against Hashem and against His MOSHIACH, saying..."
If that word looks familiar, that's because it is. King David was prophesying about the Coming King, the Coming Messiah (Moshiach) of Israel.
Here is the Orthodox Jewish Bible version of Psalm 2:7 (some words in parentheses mine):
7 I will declare the decree: Hashem (God) hath said unto me, Thou art Beni (My Son, i.e. Ben HaElohim Moshiach); today I have begotten thee.
So what is YHWH saying in Psalm 2:7?
"Anointed One" is translated "Christos" in Greek.
That is where we get "Jesus Christ," Yeshua, the Anointed One.
Jesus Christ is Yeshua ha Moshiach.
Moshiach is Ben HaElohim.
Yeshua the Messiah is the Son of God.
And what does YHWH tell everyone to do in the verses following?
11 Serve the Lord with reverential awe and rejoice with trembling.
12 Pay homage to the Son or He will be angry and you will perish in your rebellion, for His anger may ignite at any moment. All those who take refuge in Him are happy.
Do you get what He said?
He says we are to worship Jesus, the Son of God.
And when we do, that is when we will finally be happy.