54Jesus replied, "If I glorify myself, my glory means nothing. My Father, whom you claim as your God, is the one who glorifies me. 55Though you do not know him, I know him. If I said I did not, I would be a liar like you, but I do know him and keep his word. 56Your father Abraham rejoiced at the thought of seeing my day; he saw it and was glad." 57"You are not yet fifty years old," the Jews said to him, "and you have seen Abraham!" 58"I tell you the truth," Jesus answered, "before Abraham was born, I am!" 59At this, they picked up stones to stone him, but Jesus hid himself, slipping away from the temple grounds.

JOHN 8:54-58 (NIV)

The hearers of Jesus Christ knew what Jesus was trying to say..... they understood the meaning of Jesus calling Himself as "I am" (v.8) and what was their response? They would like to stone Jesus Christ for blasphemy.

The problem with some of the cults is that they inject "their meaning" to the text (eisogesis) instead of getting what the text is trying to say (exegesis). There are many texts in Scripture that when Jesus claimed His Divinity, His listeners knew the implication. Clearly Jesus is not just a "reflection" of God or a "sample" of God.

As others pointed out, Jesus clearly had no beginning. In fact, Paul wrote that Jesus embodied full-deity as His Father in Colossians : 19For God was pleased to have all his fullness dwell in him, 20and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross. (Col 1:19-20 NIV)

The theology of the Christadelphians is a mixture (or hybrid) of Gnosticism. I hope and pray that God may make this clear to you James. Because our salvation not only depending on our confession that Jesus is our Savior but who He really is.... God Eternal.