I know The Son existed before all times, and he is of the same substance of The Father. However, I get confused with the idea of "begotten". Can you explain?
I believe everyone struggles to understand the incarnation.
Jesus took on the form of a man (begotten), but Jesus did not have an earthly father. So Jesus is not a full blooded descendant of Adam.
Begotten and not created, means Jesus chose to take the form of a man, to accomplish His divine mission. Jesus was not technically a man as we understand the term. Though Jesus was a flesh and blood male, the truth is Jesus actually came from above. This is the critical distinction between Jesus and us.
John 3:13
No one has ascended into heaven, but He who descended from heaven, the Son of Man.
John 3:31
He who comes from above is above all, he who is of the earth is from the earth and speaks of the earth.
John 3
He who comes from heaven is above all.
John 6
33 For the bread of God is that which comes down out of heaven, and gives life to the world.
John 6
38 For I have come down from heaven, not to do My own will, but the will of Him who sent Me.
John 6
58 This is the bread which came down out of heaven; not as the fathers ate and died; he who eats this bread will live forever.
John 6
62 What then if you see the Son of Man ascending to where He was before?
John 7
29 I know Him, because I am from Him, and He sent Me.
John 8
14 Jesus answered and said to them, “Even if I testify about Myself, My testimony is true, for I know where I came from and where I am going.
John 8
23 And He was saying to them, “You are from below, I am from above; you are of this world, I am not of this world."
John 8
42 Jesus said to them, “If God were your Father, you would love Me, for I proceeded forth and have come from God.
John 8
58 Jesus said to them, “Truly, truly, I say to you, before Abraham was born, I am.”
John 13
3 Jesus, knowing that the Father had given all things into His hands, and that He had come forth from God and was going back to God.
John 16
28 I came forth from the Father and have come into the world; I am leaving the world again and going to the Father.
John 16
30 Now we know that You know all things, and have no need for anyone to question You; by this we believe that You came from God.
John 17
8 for the words which You gave Me I have given to them; and they received them and truly understood that I came forth from You, and they believed that You sent Me.