hi denisHere's my few pence worth.We need to distinguish between allegories, parables and types. Technically, they mean different things but people tend to lump them together. The usual way of distinguishing between an allegory and a parable is to say that a parable carries one main truth and the details are incidental; whereas in an allegory all the details are relevant. John's gospel has no parables but does have allegories; shepherd, door, bread etc. The first three gospels have no allegories but many parables. Perhaps the most famous 'allegory' is Pilgrim's Progress.“For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman. But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise. Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar.” (Gal. 4:22-24, KJVS) This is the Greek word 'allegoreo" and this is the only time it is used in the scripture. So Paul plainly used an 'allegory'. Then there are 'types'; most narratives in which the story can be used as an 'allegory' with lots of points illustrating many truths. The word 'type' in this sense is used very clearly in “Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam’s transgression, who is the figure of him that was to come.” (Rom. 5:14, KJVS) The word 'figure' is 'tupos' in Greek which is where we get the word type. Adam was a 'type' of Jesus; this is one of the most important types in the book but often forgotten. The Greek word 'tupos' is also used in “Now these things were our examples, to the intent we should not lust after evil things, as they also lusted. Now all these things happened unto them for ensamples: and they are written for our admonition, upon whom the ends of the world are come.” (1Cor. 10:6,11, KJVS) This again is the word 'tupos' so all the events of the exodus can be seen as 'types'. Here is a list of the other uses of 'tupos' in the NT, it will help to see how the word is used; John 20:25; Acts 7:43-44; 23:25; Rom. 5:14; 6:17; 1Cor. 10:6,11; Phil. 3:17; 1Th. 1:7; 2Th. 3:9; 1Tim. 4:12; Titus 2:7; Heb. 8:5; 1Pet. 5:3I think from you question you have 'types' in mind rather than 'allegories'. A 'type' gives us a pattern much like a shadow. The type or shadow gives the outward shape and can often be very helpful but we must remember that the New Testament is concealed in the Old, and that the Old Testament is revealed in the New. The greater detail and all the true colours will be seen in the New Testament reality rather than in the Old Testament 'shadow'.Now, is 'typology' a legitimate method of Bible study and teaching? Spurgeon said that illustrations were like windows and their purpose was to illuminate. He said that 'stained glass' windows failed because their purpose was not illumination but decoration. He then went on to encourage his students to use illustrations but with this warning, that windows are good for letting in light but you should never use glass as a foundation. There is tremendous wisdom in this short saying. A doctrine should never begin with a type or depend upon a type; types are illustrations. Typography has gained a bad reputation because people have used OT illustrations as 'proofs' or 'foundations' for doctrine; they should not be used in this way. However, as illustrations of solid Biblical truth they can serve as very valuable 'outlines' which help people to grasp truth. Some preachers would like to ban them altogether; I think the cure for ab-use is right use, not an outright ban.