The obedience of the Son…stands behind the assurance that those whom the Father has given to the Son will be preserved to the end, and will be resurrected on the last day. In other words, if any of them failed to achieve this goal, it would be the Son’s everlasting shame: it would mean either that he was incapable of performing what the Father willed him to do, or that he was flagrantly disobedient to his Father. Both alternatives are unthinkable, not because he never experienced the temptation to disobey, but because succumbing to the temptation, however acute that temptation might be, was itself unthinkable to him. D.A. Carson.