This answer focuses on the Pre-Nicene and Nicene period of High Christology. It explains the paradoxical phrase "begotten not made" of the Nicene Creed in light of the Scriptures and of the Ante-Nicene church.
The early church was not afraid to use Proverbs 8:22 (LXX) as their proof text that Christ is of same nature with the Father .
PROVERBS 8:22 GREEK OT: Septuagint with Diacritics:
22 ΚΎΡΙΟΣ ἔκτισέν με ἀρχὴν ὁδῶν αὐτοῦ εἰς ἔργα αὐτοῦ
23 πρὸ τοῦ αἰῶνος ἐθεμελίωσέν με ἐν ἀρχῇ
22 The Lord created me the first of his way before his ways.
23 I was made from eternity, and of old before the earth was made.
The Lord created Jesus – the first creation — from eternity before all things (Proverbs 8:22-23 LXX).The language of “creating” has more than one meaning in the Biblical context.
The Scriptures reveal two types of creating (making, producing) :
1) Creation ‘ad extra’ (from outside one’s being).
2) Creation ‘ad intra’ (from one’s being).
Creation ‘ad extra’ (from outside one’s being)
To make something or someone that is non-existent to become existent. This type of creation goes hand in hand with creation ex nihilo (Hebrews 11:3). The product is always not the same in nature with its maker.
God created the trees (Genesis 1:12). The trees were created outside God’s being (Hebrews 11:3).The trees do not have the nature of being God.
Creation “ad intra” (from one’s being)
To make someone have one’s nature. This is about “begetting” in and of itself. The offspring is always of same nature with the parent.
Abraham begat Isaac (Matthew 1:2).Isaac was created from Abraham’s being. Isaac is of same nature with Abraham. Isaac is fully human the way Abraham is. Isaac has the nature of being human.
Man begets man (Matthew 1:2-16).God begets God (John 1:18). This biblical paradigm shows that Jesus had no beginning of existence.
Both Trinitarians and Arians agree that the Son is produced from the Father. But they do not agree on what it means to be ‘begotten.’ For Arians, it means “to make someone have a beginning of existence” but for Trinitarians, it means “to make someone have one’s nature.”
The earliest Christians believed that Christ, who was identified as Wisdom in Proverbs 8:22 (LXX), was the first creation (Protoktistos) of God  but they did not view it in the sense of creation ex nihilo but rather, only in the sense of creation ad intra .
That is, the early church believed that Jesus was the first begotten (Prototokos) of every creature just as the NT teaches . It means that Jesus was the first creation -- ad intra (begetting) and all other creation were created -- ex nihilo .That is, Jesus was “made” in the sense of “begetting” (i.e. to make someone have one’s nature) and not in the sense of ex nihilo (i.e. creating someone or something from non-existence to existence).Therefore, we may only call Christ an “offspring” and never a “creature.”
On the other hand, in the early fourth century, Arius began to teach a new doctrine that Jesus Christ was the first creation in the sense of creation ad extra and ex nihilo .But the church stood still. The Nicene Creed was a reaction against the new doctrine taught by Arius’ . The church upheld the ancient faith that the Son was “begotten (made ad intra) not made (ad extra/ex nihilo), of same substance (nature, essence) with the Father” .
Bottom Line: Man begets man (Matthew 1:3). God begets God (John 1:18). This biblical paradigm is useful for teaching doctrine (2 Timothy 3:16-17).This biblical paradigm supports the biblical teaching that Jesus Christ had no beginning of existence because he is the [only] begotten Son of God (John 1:18; 3:16).
Conclusion: In Proverbs 8 (LXX), Verse 25 explains verse 22: Jesus is begotten from the Lord. God shared his whole nature to Son. The Son is the exact likeness of God's being (Hebrews 1:3).
Proverbs 8:22-25 teaches that Jesus Christ was the first activity inside God’s being, that is, He the first creation “ad intra” (the first begotten) from the Father. This reveals that Colossians 1:15-16 is an allusion to Proverbs 8:22-25.
 http://www.christian-history.org/trinity-heresy.html] http://biblehub.com/commentaries/proverbs/8-22.htm
Clement of Alexandria. Who is the Rich Man that Shall be Saved? Section 12. Proverbs 8:22 (Septuagint) Sirach 24:9 (Septuagint)
 Psalm 110:3 (Septuagint), Proverbs 8:25 (Septuagint), John 1:18; 3:16
Colossians 1:15-16 (GNV, 1599).
 Genesis 1:11-12, Colossians 1:16-17; Hebrews 1:2, 10;11:3