Several kinds, good and bad
In Bible interpretation we should reject bad allegory, that is to say, looking for an alternate meaning of a passage. But some stories and parables are clearly intended this way — good allegory.
Paul uses the word "allegory" one time only, and in so doing gives the events in question a very different meaning than originally. We (non-apostles) can't do this, change the meaning; only the apostles can, being the authority for Christian truth.
Bad Allegory — these are literal
These examples are literal, not allegorical...
- The image of the wolf lying down with the lamb is a literally true representation of a common occurrence in the new heavens and new earth.
- A good example of the misuse of allegory is the various interpretations of the Song of Solomon. Only I interpret it literally, as a nonfiction poem by Solomon about his relationship with his first wife, the wife of his youth.
- Jesus is literally the sacrificial lamb of God, he mystically appears as this on the altar during the Eucharist.
- Images in the heavenly realm of creatures living there: all literal. As we pray here on earth, angelic beings perform ritualistic worship in heaven, offering our prayers in tangible form to God.
- Ezekiel 37:24 literally occurs in the new heavens and new earth. David rules as king over the restored land of Israel over the 144,000.
- Isaiah 35:1 has flowery language, but literal. Does the desert literally rejoice? Why yes, it does. In the spiritual realm there is a spiritual place corresponding to every place in the physical realm, and each spiritual place is living, full of life, capable of rejoicing. Spiritual stones can worship God. Why would Jesus say the stones would cry out in recognition of his being Messiah, king of Israel, if it were just a poetic phrase having no meaning?
- Jesus is literally a shepherd; we, his disciples are literally sheep, these events all occurring in the spiritual realm. The world of dreams is a real world, a spiritual world, and its images are real. Just as we act out dreams with a dream body, so also we act out our salvation via our spiritual body corresponding to our physical body.
The error is in thinking the mind is unreal, but of course it is real. Thoughts, ideas, symbols, dreams, really exist and our soul experiences them in the same way our physical senses experience light, color, sound, touch.
- Usually the armor of God is thought of as a mere puzzle; try to match up characteristics of each piece of Roman armor with each image. For example: righteousness has something to do with protecting the heart and lungs; faith protects us from attacks of the enemy; the gospel and its proclamation has something to do with the feet and what the feet do — walking or running.
I doubt if Paul had any of this in mind when he wrote it.
The armor of God is not a teaching about the faith but, rather, a way to hold the key concepts in our mind, a mnemonic aid similar to icons, prayer beads, meditation images; an early devotional like the Sacred Heart of Jesus or Divine Mercy Chaplet.
These images are literal, of Paul imagining a soldier superimposed upon a Christian, the life of battle juxtaposed upon the life of faith. It's all literal just as the images of Christ's second coming are literal; something for our mind to meditate on to draw us into the heavenly realms where Jesus resides.
These examples are allegory; the writer clearly intended this...
- Early in the Old Testament the images of improper relations became an allegory for worship of false gods.
- Israel is referred to as a vine but the Old Testament clearly states this designation. Israel is also referred to by other terms such as "well-beloved".
- A little allegorical story.
- The Church = Israel