Charles Spurgeon Commentary John 18:16-18

"but Peter was standing at the door without. So the other disciple, who was known unto the high priest, went out and spake unto her that kept the door, and brought in Peter. The maid therefore that kept the door saith unto Peter, Art thou also [one] of this man`s disciples? He saith, I am not. Now the servants and the officers were standing [there], having made a fire of coals; for it was cold; and they were warming themselves: and Peter also was with them, standing and warming himself." — John 18:16-18 (ASV)

Then went out that other disciple which was known unto the high priest and spake unto her that kept the door and brought in Peter. Then saith the damsel that kept the door unto Peter, "Art not thou also one of this man's disciples?" He saith, "I am not." And the servants and officers stood there, who had made a fire of coals, for it was cold: and they warmed themselves; and Peter stood with them, and warmed himself.

Peter was in bad company; while he was warming his body, his soul was growing cold to his Master. People cannot go into bad company without getting some hurt. It is said by a quaint old writer that, if people go to Ethiopia, they may not become Ethiopians, but by the scorching of the sun they will grow blacker than they were before. It is always better to keep out of harm's way if we can. Whoever would not fall into a ditch should take care not to walk near the edge of it; so, if Peter wanted to stand fast, he should not have gone where he would be sure to be tempted.