Obviously if the Torah and Injeel were corrupted, that means they return to God empty. God says His Word will not return to Him empty.
The Word of God accompishes what God desires from it, and achieves the purpose that God wishes. Christianity was intended to teach that Christ was the Lord and Savior. Christ did die for our sins and was raised, that is fully supported in scripture. The Gospel was a major success and it accomplished the purpose that God wished because Christ accompished the purpse that the Father wished, and the Gospel records the life of the real Jesus Christ
What does empty mean? Lets check a dictionary.
emp·ty ( P ) Pronunciation Key (mpt)
adj. emp·ti·er, emp·ti·est
Holding or containing nothing.
Mathematics. Having no elements or members; null: an empty set.
Having no occupants or inhabitants; vacant: an empty chair; empty desert.
Lacking force or power: an empty threat.
Lacking purpose or substance; meaningless: an empty life.
Not put to use; idle: empty hours.
Needing nourishment; hungry: “More fierce and more inexorable far/Than empty tigers or the roaring sea” (Shakespeare).
Devoid; destitute: empty of pity.
[Taken from www.dictionary.com ]
So, if the scriptures return to God empty, that means that they have nothing in it. It does not mean corrupted.