Dave Burke, a leading apologist for “Biblical Unitarianism” from Australia (he debated [and defeated] Robert Bowman in 2010 on the Trinity) wrote the following under the screen name of “Evangelion” (emphasis in original) in an attempt to neutralise John 17:5 as a valid "proof-text" for Jesus' pre-existence:
In Genesis 15:18, for example, God says that He has given the land of Canaan to Abraham and his seed, yet Abraham never possessed the land, and he still does not have it to this day.
God referred to this gift in the past tense, but Abraham understood that He used figurative language. He knows that God meant "The land is predestined to be the land of you and your seed." (Source)
There is no meaningful parallel between John 17:5 and Gen 15:18.
In Gen 15:18, the Lord does not say that Abraham had this land and that he will restore it to Abraham, while in John 17:5, Jesus says that he had glory with the Father, and is requesting for a restoration thereof.
Furthermore, in Gen 15:18 in the LXX uses the future tense of διδωμι ("to give"), δωσω (I will give), not a past tense, let alone an imperfect, as it used in John 17:5.
The attempted rebuttal by Burke is a dismal failure.
