It says all or every scripture - the canon wasn’t under discussion, but the role of scripture.
Paul tells Timothy to continue in what he has learned for two reasons: first, because he knows from whom he has learned it—Paul himself—and second, because he has been educated in the scriptures. The first of these is a direct appeal to apostolic tradition, the oral teaching which the apostle Paul had given Timothy.
The Bible denies that it is sufficient as the complete rule of faith. Paul says that much Christian teaching is to be found in the tradition which is handed down by word of mouth (2 Tim. 2:2). He instructs us to "stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter" (2 Thess. 2:15).
This oral teaching was accepted by Christians, just as they accepted the written teaching that came to them later. Jesus told his disciples: "He who hears you hears me, and he who rejects you rejects me" (Luke 10:16). The Church, in the persons of the apostles, was given the authority to teach by Christ; the Church would be his representative. He commissioned them, saying, "Go therefore and make disciples of all nations" (Matt. 28:19).
And how was this to be done? By preaching, by oral instruction: "So faith comes from what is heard, and what is heard comes by the preaching of Christ" (Rom. 10:17). The Church would always be the living teacher. It is a mistake to limit "Christ’s word" to the written word only or to suggest that all his teachings were reduced to writing. The Bible nowhere supports either notion.