I Timothy 3:15 is often cited by Catholic apologists in response to Sola Scriptura. It reads:
14 So much I tell thee by letter, although I hope to pay thee a visit before long; 15 so that, if I am slow in coming, thou mayest be in no doubt over the conduct that is expected of thee in God’s household. By that I mean the Church of the living God, the pillar and foundation upon which the truth rests. — Knox Bible
I just re-read the passage, and somehow feel that one could also read this as “God is the pillar and foundation of the Truth”. I can’t read Greek, so I don’t know whether it is clearer in the grammar.
What’s meant, God or the Church?