NOTES for Co1 15:3-5
Paul's words about the Savior's death and resurrection with the addition "according to the Scriptures" are very curious. Which "writings" are meant? The corresponding Hebrew word denotes the third part of the Jewish canon of Holy Scripture, which formed considerably later.
In Paul's time the Holy Scripture of Judaism included the Torah, the Former Prophets (our historical books, except for Chronicles), and the Latter Prophets (our prophetic books, except for the Book of Daniel, which in the Jewish canon does not belong among the prophetic books).
In the New Testament books the Jewish canon of Holy Scripture is usually called "the Law and the Prophets," by which are meant precisely the Torah (that is, the Pentateuch) and the prophetic books (the Former Prophets and the Latter Prophets). The third part of the Jewish canon, which is called by the word "Writings," formed considerably later, in the third and fourth centuries A.D. This third part included our wisdom books, as well as Chronicles, Psalms, and Daniel.
These books appeared much earlier, even before Christ came, but in those days the Synagogue regarded them as authoritative books useful for reading, though not included in the canon of Holy Scripture. The composition of the "Writings" was therefore not precisely fixed; it varied depending on region and local traditions, often including books not only in Hebrew, but also in Greek.
It is not excluded that the first generation of Christians also had its own version of the "Writings." These were not yet, of course, the Gospels we know, but their core may have been written down already in those times.
Indeed, the foundation of all four Gospels is the account of the Savior's resurrection, which is not surprising: the Resurrection is the brightest and unique testimony to Jesus' messiahship and to the truth of His words about the Kingdom He brought into the world. The preaching of Paul, as well as that of all the other apostles, was built on the testimonies to the Resurrection.
Meanwhile, the account of the Resurrection is, in form, a collection of testimonies, and such testimonies need the most exact possible recording. It is no wonder that testimonies of people connected with the Resurrection began to be recorded and systematized very early, already during the lifetime of the first Christian generation.
These written accounts were, it appears, well known to the first Christians, and Paul could refer to them, confident that his listeners knew what he had in mind. Thus personal testimony was supplemented by written sources: written sources were testimony to the reliability of the Resurrection as a real historical event, while personal experience, witnessed by such witnesses as Paul himself, for example, proved that the Resurrection is not only history, but also the reality of the life of every Christian, regardless of where and when he lives.