Bible prophecy is a promise from God about what is certain to happen in the future. God has given us many promises concerning Israel, the Anointed One and End Times (The Last Days). Many people believe prophecy is very general and obscure. However, we must not confuse human prophecy with divine prophecy. Human prophecy must be vague because it is impossible for a human to accurately predict specific events hundreds and thousands of years into the future without being wrong even once.
Only God can tell the future with 100% accuracy.
In order to be a prophet from God, you must prophesy. If you claim to be a prophet yet fail to prophesy, you are a false prophet. If you attempt to prophesy and are wrong just once, you are also a false prophet. Several self-proclaimed "Christian" organizations who study another book of faith besides the Bible are exposed as false by God's own standard for his prophets, which is perfection. Several world religions have books of faith which contain miniscule amounts of prophecy or none at all. Because of this fact, these religions are immediately disqualified as being divinely inspired by God.
Read what God himself has to say about this subject:
Read some of the greatest prophecies in the Bible:
Read prophecies concerning the Anointed One:
Read prophecies concerning End Times: