At the end of Mark 14, we read of how Peter, who at one time bragged that he would never forsake Jesus, did just that. He betrayed Jesus not once, but three times. J. C. Ryle comments:
The experience of Peter is only the experience of all God’s servants who have yielded to temptation. Lot, and Samson, and David, and Jehoshaphat in Bible history–Cranmer and Jewell in the records of our own English Church–have all left evidence, like Peter, that “the backslider in heart shall be filled with his own ways.” (Prov. 14:14.) Like Peter, they erred grievously. Like Peter, they repented truly. But, like Peter, they found that they reaped a bitter harvest in this world. Like Peter, they were freely pardoned and forgiven. But, like Peter, they shed many tears.