I asked one of the JWs who were in my house for the Bible study (their way) and they said, "See the word, firstborn? That means Jehovah created him." I told them what it really meant, (*)but they sticked to their argument that according to their Bible (which it is shown below), it meant Jesus was created.
(*)According to the Got Question website it explains:
Question: "What does it mean that Jesus is the 'first-born' over Creation?"
Answer: In a letter to the church at Colossae, the Apostle Paul gave an intriguing description of Jesus. In it, he explained Christ's relationship to God the Father and to creation. Some have claimed that Paul’s description of Christ as the first-born of creation means that Jesus was created -- not eternal, not God. Such a doctrine, however, conflicts with the rest of the Bible. Christ could not be both Creator and created; John 1 clearly names Him Creator. Let’s take a careful look at the passage where Jesus is called the first-born.
“And He is the image of the invisible God, the first-born of all creation. For by Him all things were created, both in the heavens and on earth, visible and invisible, whether thrones or dominions or rulers or authorities — all things have been created by Him and for Him. And He is before all things, and in Him all things hold together. He is also head of the body, the church; and He is the beginning, the first-born from the dead; so that He Himself might come to have first place in everything. For it was the Father's good pleasure for all the fullness to dwell in Him, and through Him to reconcile all things to Himself, having made peace through the blood of His cross; through Him, I say, whether things on earth or things in heaven.”
Jesus is God
Christ’s relationship to His Father begins with the phrase "the image of the invisible God." The word “image,” meaning copy or likeness, expresses Christ's deity. This word involves more than a resemblance, more than a representation. He is God! Although He took on human form, He has the exact nature of His Father (Hebrews 1:3).
The "Word" of John 1:1 is a divine Person, not a philosophical abstraction. In the incarnation, the invisible God became visible in Christ; deity was clothed with humanity (Matthew 17:2). God is in Christ: visible, audible, approachable, knowable, and available. All that God is, Christ is.
Jesus is Lord of Creation
The description "first-born of all creation" speaks of Christ’s preexistence. He is not a creature but the eternal Creator (John 1:10). God created the world through Christ and redeemed the world through Christ (Hebrews 1:2-4).
Note that Jesus is called the first-born, not the first-created. The word "first-born" (Greek word "prototokos") signifies priority. In the culture of the Ancient Near East, the first-born was not necessarily the oldest child. First-born referred not to birth order but to rank. The first-born possessed the inheritance and leadership.
Therefore, the phrase expresses Christ's sovereignty over creation. After resurrecting Jesus from the dead, God gave Him authority over the Earth (Matthew 28:18). Jesus created the world, saved the world, and rules the world. He is the self-existent, acknowledged Head of creation.
Finally, the phrase recognizes Him as the Messiah: "I will make Him [Christ] My first-born, higher than the kings of the earth" (Psalm 89:27).
Six times the Lord Jesus is declared to be the first-born of God (see Romans 8:29; Colossians 1:15, 18; Hebrews 1:6; 12:23; Revelation 1:5). These passages declare the preexistence, the sovereignty, and the redemption that Christ offers.
Thus, the phrase "first-born of all creation" proclaims Christ’s preeminence. As the eternal Son of God, He created the universe. He is the Ruler of creation!
If you compare Col. 1: 15-21 to the NWT there are difference regarding Jesus. The terms in italics the NWT added [other]. For example:
NWT : 15 He is the image of the invisible God, the firstborn of all creation;
16 because by means of him all [other] things were created in the heavens and upon the earth, the things visible and the things invisible, no matter whether they are thrones or lordships or governments or authorities. All [other] things have been created through him and for him.
17 Also, he is before all [other] things and by means of him all [other] things were made to exist,
18 and he is the head of the body, the congregation. He is the beginning, the firstborn from the dead, that he might become the one who is first in all things;
19 because [God] saw good for all fullness to dwell in him,
20 and through him to reconcile again to himself all [other] things by making peace through the blood [he shed] on the torture stake, no matter whether they are the things upon the earth or the things in the heavens.
So according to them John 1:1 Jesus was a god. So therefore, that is why they believed that Jesus was created. Of course they cannot disagree with what the the Watchtower tells them.
Hope that answers your question.
God wants spiritual fruits, not religious nuts.