R.C Sproul in his defense of divine impassibility is wrong in this following statement
Some say, “It was the second person of the Trinity Who died.” That would be a mutation within the very being of God, because when we look at the Trinity we say that the three are one in essence, and that though there are personal distinctions among the persons of the Godhead, those distinctions are not essential in the sense that they are differences in being. Death is something that would involve a change in one’s being.
God has changed and God did change. Scripture tells us that there was a time where God was not the creator. Before creation God existed – and therefore through the creation process he changed in becoming the creator. Within the framework of existence the Incarnation changed God. There was a time when God was not the God incarnate. There was a time when the 3rd member of the Trinity was not the Incarnate Jesus Christ. And the 3rd person of the Trinity the incarnate Jesus Christ, now sits at the right hand of God the Father, in his resurrected incarnate state, with the scars of the cross in his head, back, hands, feet and side – as an eternal intercessor for all of humanity.
We don’t know the what and how the pre-incarnate member of the Trinity looked. But, we do know he was always divine and through the incarnation, the third member of the Trinity has forever changed.