There were no written gospels when Paul wrote these letters. Yet the letters were written to Christians—that is to say to people who had heard and believed the gospel story. But they knew it in an oral form, not in written records. Since they knew it, however, it was not necessary for Paul to relate it in his letters to them, except when, for purposes of his own, he thinks it wise to remind them of the gospel which they had heard from his lips. He does this, for example, at the beginning of 1 Corinthians