Sure a lake of fire is an analogy. But "eternal punishment" seems pretty clear and not an analogy.
Taking parables literally obviously we shouldn't do. But interpreting them and building a theology around them seems to be exactly what Jesus wanted. Jesus even interpreted some of them for his apostles (Mark 4:3-20).
Jesus never said we should take scripture as our sole source of truth and ignore other sources. Jesus gave the power to guide the Church to his apostles, and specifically Peter (Matthew 16:18). We can even see the apostles using this power in Acts 15 to establish doctrine. A good explanation of this is in this video[1]. They can continue to use this power at the council of Nicea.
Taking parables literally obviously we shouldn't do. But interpreting them and building a theology around them seems to be exactly what Jesus wanted. Jesus even interpreted some of them for his apostles (Mark 4:3-20).
Jesus never said we should take scripture as our sole source of truth and ignore other sources. Jesus gave the power to guide the Church to his apostles, and specifically Peter (Matthew 16:18). We can even see the apostles using this power in Acts 15 to establish doctrine. A good explanation of this is in this video[1]. They can continue to use this power at the council of Nicea.
[1] https://www.youtube.com/watch?v=jJCbCs-y1_k