Peter's last denial
"Man, I do not know what you are talking about" (Luke 22:60, HBFV throughout)
The above are Peter's last words that sealed his three-fold denial of being one of Jesus' disciples. Christ prophesied this rejection of him would happen before the cock crowed (Matthew 26:34, 75). Interestingly, the gospels complement each other's accounts of this incident.
Matthew and Mark record that this New Testament event took place in the High Priest's courtyard (Matthew 26:69, Mark 14:66). All four gospels state Peter's first denial was spoken to a woman. Matthew and Mark state his second denial was also said to a female, while Luke indicates it was a man.
Luke also reveals the third denial was toward a man (Luke 22:59 - 60). John states this person was a High Priest servant whose relative had their ear cut off by Peter (John 18:10, 26). Matthew and Mark reveal Peter used curse words during his last denial. On a final note, according to Luke, after his third denial Jesus turned from inside the priest's house and looked at Peter (Luke 22:61).
Sin and suicide
"I have sinned and have betrayed [delivered up, surrendered] innocent blood" (Matthew 27:4)
Judas' betrayal of Jesus required the devil to possess him to insure the act was carried out (John 13:27). Judas, after Satan leaves him, begins to come to terms with what he did and feels remorse for betraying man's Savior. His last words above, in the only place they are recorded in the New Testament, are given just moments before he returns the "blood money" he received for his deed. After throwing his thirty pieces of silver onto the temple floor, he leaves to commit suicide (Matthew 27:5).
Forgiveness and murder
"Lord, do not lay this sin to their charge" (Acts 7:60)
The above last words come from Stephen moments before his death by stoning at the hands of zealous Jews. Stephen was one of the first leaders in the early Christian church, a man the Bible twice labels as being full of faith and the Holy Spirit (or power, see Acts 6:5, 8).
Although Stephen performed "wonders and great signs" (verse 8) as confirmation of what he taught, it was his ability to refute the false teachings of Hellenistic (Greek speaking) Jews that got him dragged before the Sanhedrin (verse 12). His defense of what he believed (the longest speech in Acts) so enraged the Jewish religious authorities that it sealed his fate as the first New Testament martyr.
Last words of rebuke
"For I perceive that you are in the gall [poison] of bitterness and the bondage [under the control] of unrighteousness" (Acts 8:23).
Simon Magus was a man willing to work with the devil for the sole purpose of enlarging his own vanity. Magus, using black magic, had performed false miracles for such a long time in Samaria that it earned him the respect of even the most influential people (Acts 8:9 - 11). When Philip visited Samaria, he saw firsthand what REAL miracles looked like (verse 13).
Magus was further amazed and intrigued when he witnessed people receiving God's Spirit through the hands of Peter and John. Believing they possessed, and had authority over, such power (instead of it being dispensed through them at God's discretion), he offered money to obtain this ability for himself. Peter strongly rebuked him, with his last words above summarizing Simon Magus' true spiritual state which ultimately sought to make a profit off of a gift from God.