A lesson on the weakness of the flesh, and the power of God's sustaining grace, for the perseverance of His saints. The natural inclination of the mind set on the flesh is to overestimate it's own strength, and to divert the attention of failure away from itself. Peter is a case study of a disciple who, while genuine in his faith and devotion to Christ, lacked awareness of this weakness within himself. For all his proud and lofty claims of backing Jesus whatever may come, his perception would in a moment be shattered, for it would only be a matter of hours before he would end up denying Jesus three times. Yet the crucial distinction between Judas and Peter was that unlike Judas, who died unrepentant, Peter's faith was upheld by God's mighty hand even to the end.
In a word of practical application, all of us need a reality check. God often uses trials of faith to show us our own weakness, and to reveal our need to draw ever nearer to Himself. Yet take comfort beloved; if your faith is genuinely in Christ, He will not let your faith fail. Christ makes intercession for His people even today, and none of His sheep will He lose.