Did you get that? Paul was WRITING this letter - you know, the SCRIPTURE book of I Timothy - so that Timothy and those he taught would know how they were to act or behave in an assembly of believers (ekklesia). The "church" is supposed to hold up and support the truth as it was taught to them by Jesus and the Apostles. This truth which was written down and preserved up to even today. It didn't change. Christians STILL believe that Jesus appeared in the flesh, was vindicated by the Spirit, was seen by angels, was proclaimed among the nations, was believed in throughout the world, was taken up in glory.
Do you know English? How to diagram a sentence? The CHURCH is described by Paul as the Pillar and Foundation of TRUTH. The CHURCH. Paul never describes Scripture as the foundation of TRUTH. That is the relevant part of my argument, which you continue to ignore.
I'll repeat - What does Scripture say is the pillar and Foundation of Truth? (Hint- it is the Church Christ established.) And show your answer using Scripture.