What is typology?

Typology is a special form of symbolism wherein a person, an event, or some other thing, dramatically foreshadows a future concept. These things are called "types", or "figures", which precede an "antitype" - that which fulfills the foreshadowing. Typology seems somewhat conspiratorial, almost like "reading between the lines". However, unlike certain "Bible codes" and the like, typology is legitimised by the New Testament, even doing so using the exact words (e.g. 1 Peter 3:21).

Typology is a double edged sword, as some false religions will attempt to argue their case based on imagined "types" and "antitypes". Searching the Old Testament, they will attempt to find anything they can apply to their warped theology. A helpful safeguard against this demonic trick is, first of all, to simply stick to what the New Testament explicitly says. When the New Testament draws on the Old Testament, such as when Paul says "...they drank of that spiritual Rock that followed them, and that Rock was Christ" (1 Corinthians 10:4), we can trust that. By contrast, when a Mormon comes along and says Ezekiel 37 contains the Book of Mormon, we can reject this. A second safeguard is to simply never allow typology to be used as an argument. You may find something in the Old Testament that vaguely resembles your theology, but if it's sound theology, you won't need to argue from the shadow.