You don't understand Lee's motivation if this is what you believe. He was reluctant to resign, and his loyalty was to his state.
http://penelope.uchicago.edu/Thayer/E/Gazetteer/People/Robert_E_Lee/FREREL/1/25*.html
Lee would not despair of the Union. He was for forbearance to the last, recognizing no necessity for recourse to arms.
16 The maintenance of slavery meant nothing to him. He felt that if he owned all the slaves in the South he would cheerfully give them up to preserve the Union.17 He would hold to the army and to the flag as long as he could in honor do so.18 But during those days of suspense, Lee was confirmed in his point of view. He had been determined from the outset that he would adhere to Virginia and defend her from any foe. Now, fully, he realized that though he considered secession neither more nor less than revolution, he could not bring himself to fight against the states that regarded secession as a right. He could not think of himself as fighting with the South against the Union, unless Virginia's defense were involved, but neither, as the possibility seemed to be brought nearer, could he reconcile himself to fighting with the Union against the South. "That beautiful feature of our landscape," he said sadly one day, as he pointed to the capitol across the Potomac, "has ceased to charm me as much as formerly. I fear the mischief that is brewing there."
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He had said: "If the Union is dissolved and the government disrupted, I shall return to my native state and share the miseries of my people and save in defence will draw my sword on none." There he stood, and in that spirit, after listening to all Blair had to say, he made the fateful reply that is best given in his own simple account of the interview: "I declined the offer he made me to take command of the army that was to be brought into the field, stating as candidly and as courteously as I could, that though opposed to secession and deprecating war, I could take no part in an invasion of the Southern States." That was all, as far as Lee was concerned. He had long before decided, instinctively, what his duty required of him, and the allurement of supreme command, with all that a soldier craved, did not tempt him to equivocate for an instant or to see if there were not some way he could keep his own honor and still have the honor he understood the President had offered him. Blair talked on in a futile hope of converting Lee, but it was to no purpose.
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He came downstairs when he had finished the letters. Mrs. Lee was waiting for him. She had heard him pacing in the room above her and had thought she had heard him fall on his knees in prayer. "Well, Mary," he said calmly, "the question is settled. Here is my letter of resignation and a letter I have written General Scott."
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She understood. Months later she wrote a friend, "My husband has wept tears of blood over this terrible war,
but as a man of honor and a Virginian, he must follow the destiny of his state."
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