Are John 12:27 and Luke 22:42 contradictions?
Now is my soul troubled; and what shall I say? Father, save me from this hour: but for this cause came I unto this hour.
John 12:27
Saying, Father, if thou be willing, remove this cup from me: nevertheless not my will, but thine, be done.
Luke 22:42
The first thing to notice is that these two statements were not spoken at the same time in the historical record, that is they are two different events. John records something done in public.
John 12:27-30 Now is my soul troubled; and what shall I say? Father, save me from this hour: but for this cause came I unto this hour. 28Father, glorify thy name. Then came there a voice from heaven, saying, I have both glorified it, and will glorify it again. 29The people therefore, that stood by, and heard it, said that it thundered: others said, An angel spake to him. 30Jesus answered and said, This voice came not because of me, but for your sakes.
Luke was said in private prayer.
Luke 22:39-42 And he came out, and went, as he was wont, to the mount of Olives; and his disciples also followed him. 40And when he was at the place, he said unto them, Pray that ye enter not into temptation. 41And he was withdrawn from them about a stone’s cast, and kneeled down, and prayed, 42Saying, Father, if thou be willing, remove this cup from me: nevertheless not my will, but thine, be done.
Both statements convey the same meaning. In John he says to the people; what, you think I should ask the father to save me from this, this is why I came into the world (why the Father sent him into the world). In Luke he expresses his agony but willingness to obey the Father’s will.
I cannot see how anyone could think they contradict.