Socrates teaching was quite radical and advanced for the people in his time hence the authority felt the need to remove him altogether from the picture. He was given hemlock based poison to drink and that's when he made this great remark, "The hour of departure has arrived, and we go our separate ways, I to die, and you to live. Which of these two is better only God knows."
Notice how he mentions just God but not Gods though one of the accusations against him was that he introduced new deities and did not acknowledge the old ones. I thought that was interesting.