8:1-13 What is the core teaching of this chapter?

The core teaching here is that mature Christians demonstrate their love for those weaker in the faith by not participating in the things their faith allows, but which the weaker Christian's faith does not, and which would cause them to sin if they participated (CP Ro 14:13-23; 1 Cor 10:19-33).

The specific issue of idol-sacrificed meat in 1Cor 8 is simply the vehicle Paul uses to teach the timeless truth that love for God results in love for His children.

If we say we love God, how can we do anything that could cause another of His children to perish, for whom Christ also died (CP 1Cor 9:19-23; Ga 5:13).

How Christians show their love for each other is how they prove their love for God (CP Jn 13:34-35; 1Cor 13:1-7; 1Jn 3:11, 14, 16, 18; 4:11-12, 16-21; 5:1-2).

The teaching emanating from 1Cor 8 does not only apply to meat sacrificed to idols, but to anything at all - what we drink, what we wear, what we participate in - that could cause a weaker brother or sister to fall away from the faith and perish (CP Mt 18:6-14).