Lamb of God is a relatively simple metaphor. Some metaphors are much 'bigger'. Some are so big that we can live our whole life in them. We use science to manipulate things, manipulate our environment as we please. But we don't live in science. We live in metaphor. And ultimately we can't explain the metaphor we live in. A large percentage of people would say that when we die, we go to heaven. Others would say we lie waiting in the earth until the Lord returns at the end of the world. Still others would talk of purgatory. These aren't identical metaphors that lend themselves to being harmonized in a literal way. But in general they point to a reality beyond themselves that doesn't differ too much. They all point to getting beyond this life, to a better life. They all point to escaping an imperfect world for something more perfect. They all deemphasize the importance of now, and focus clearly on the glories of later.
Jesus' parables are masterful metaphor, common stories of the everyday world which you think know all about, only to find out at the punch line that the 'kingdom' Jesus was pointing too was an entirely unanticipated reality. Paul too used metaphor extensively. That is why they both are such powerful religious figures. Religion lives in metaphor. Myth is culturally accepted metaphor. Parable is the subversive questioning of accepted myth. They are mirror images.The thing is though, that both Jesus' parables and Paul's metaphors emphasize the importance of now, and go all fuzzy on the glories of later. Consider the parable of the lost coin. Did Jesus say the kingdom of God is like . . . waiting at a train station . . . or like hastily sweeping the floor? The parable is not about waiting for the future; it is about jumping into action. Paul constantly used metaphors, especially coming back to the resurrection metaphor over and over again. But the metaphor as Paul used it was different from the metaphor as we use it. The General Resurrection was a 1st century Judean metaphor concerned with God's remaking the present world faithfully, rather than about our leaving the present world as a reward.
To point to what the General Resurrection symbolized, J. D. Crossan coined the phrase, 'The Great Divine Cleanup of the World'. For Paul, the General Resurrection, the Divine Cleanup, had already begun, and Jesus was the 'first fruits'. The Cleanup is not in the distant future, after death, or in the imminent future . . . soon. It has already begun, and we already live in it. So live accordingly! Now! When Paul talks about the 'people who get it right', as he does in all his letters, and especially in Romans, he has in mind the people who trust that God actually is in process of cleanup, who trust to the point of collaborating with God on the project, who form little communities that together work on the cleanup. And also for Paul, the 'people who get it wrong' are the people who trust in their religious traditions instead. 'Jews' then have become 'the churched' now. 'Gentiles' then have become 'the unchurched' now.
When one talks about the 500 Year Garage Sale, about why mainline churches are declining, about how the Reformation church can renew itself for the next 500 years, Jesus' parables of the kingdom, and Paul's metaphor of the General Resurrection matter. A post Garage Sale church could end up with people selling every possession, waiting breathlessly for some eagerly anticipated great event to occur, maybe on a cleverly forecast date. A post Garage Sale church could end up with people waiting at a train station, sleepily singing hymns that have lost their umpf, to pass the time. Or a post Garage Sale church could be collaborating with God's Divine Cleanup, now. Which one sounds like life to you? Metaphors matter.