Strobel applied his skills learned as an investigative journalist for the Chicago Tribune to his iinterviews with physicists, molecular biologists, theologians, and historians, and concluded that it is likely that the resurrection of Jesus took place as described by the four authors of the gospels. Particularly in reference to the historical record, Strobel argued that if one applies the same standards historians routinely use to establish accuracy of evidence, it is very likely that the gospels are at least as accurate as other major events in history that are generally accepted as fact. These standards include the availability, reliability and number of eyewitness accounts, as well as the reliability of those who wrote down their claims: three of the four, Matthew, Mark, and John, knew Jesus personally. Matthew and John served as his apostles, and Mark first knew of Jesus when he was a teenager, when his mother was hanging around with Jesus and his crowd. Strobel concludes that when standard tests of evidence analysis are applied, these gospels, are indeed non-fiction.