Matthew 26:57-58 (also Mk. 14:50-55; Lu. 22:54-56; Jn. 18:12-17)

Those who had seized Jesus led Him away to Caiaphas, the high priest, where the scribes and the elders were gathered together. 58 But Peter was following Him at a distance as far as the courtyard of the high priest, and entered in, and sat down with the officers to see the outcome.

Of the four gospels Luke was somewhat the same as Matthew, but Mark’s and John’s gospel had more to add. Mark included a young man (probably himself) who was taken captive but managed to escape naked when he pulled free of his loose clothing. John’s gospel includes another disciple (also, probably John himself) who was following Jesus with Peter, who helped Peter to enter with him into the courtyard of the high priest.

For some reason Peter was unable to enter the courtyard and stood at the doorway before John helped him come in; for John knew the high priest and he also had some influence with the doorkeeper. Hence I take it that John was more friendly with people, and Peter was not. But we don’t really know why the doorkeeper would not let him in.