St Paul wrote this epistle about 30 years after Jesus' completed work on the cross. The fledgling Christians were only becoming to understand that they would be distinctly separate from Judaism. They had been a sect, albeit a troubling one for the Jews, of Judaism.
When you read the Epistles, the only Scripture they were referencing was the Septuagint, or the Old Testament. St. Paul wasn't calling his letters Scripture. Protestants like to imagine that the KJV Bible was handed out on the first Resurrection Sunday. Well, we know that's not true and we also know that some of the New Testament wasn't even written until after the letter to Timothy.
Necessarily then, the Church needed to be the pillar and foundation of truth. St Paul regularly exhorts them to hold fast to the doctrines that they were taught either by word or letter.
We know that many other writings of the early church fathers were also held in high esteem and read from in the early church. Imagine a time period almost twice as long as the USA has been in existence without a definitive canon. The Church was the holder of the faith. It was, and is, it's defender.
The Church, led by the Holy Spirit, held strong to maintain the faith that was handed down to them. Jesus led them and never forsook them. The biblical canon, even the Protestant canon was a product of the Church in unison with the Holy Spirit, and as led by Jesus the Christ.
To have faith in Jesus, and to have faith in the New Testament, is to have faith in the Church. Period. It can't be separated. Isaiah 9:6-7 says the government of this Church would be on His shoulders, and He will increase it, establish it, and uphold it.