Revelation is when something that was previously hidden is revealed.
The Revelation Game
Look! There is a box! I wonder what is inside it? Any ideas?
Go on - have a good guess - what could it be? Something fun? Serious? Exciting?
Hooray - the box is open! What has been revealed?
My favourite thing ever: a Rebel Snowspeeder used on the planet Hoth in the Empire Strikes Back!
The 'Big' things revealed
Okay - more serious now - the revelation game is a bit like our everyday lives only we are inside a box!
What is beyond the universe? What happens beyond death? Was there a beginning to things? What is it all about? We are inside a box longing for big answers to big questions.
Much like the revelation game above we can (and do) spend lots of time guessing about the answers. Many people have spent their entire lives doing this.
Can anyone find the answers by guessing, or is something more needed?
Revelation: when the 'big' answers that were previously hidden are revealed by God
Here is where many of the major world religions agree - they often believe that there are answers to the 'big' questions. They believe that God (in whatever form that may be) has revealed information to assist us inside our box.
e.g. Muslims believe that God sent messages to the Prophet Muhammed (the Qur'an) that provide the necessary information we seek.
Christians claim a similar thing with the Bible, and particularly in Jesus Christ. They believe that God has turned up in person to our box.
God bringing answers to us from beyond
It doesn't take very long to see that although there might be common ideas among the different world religions, there are also unique claims and beliefs in each group. It would be grossly unfair to lump them all together as if they were the same thing.
So although they have different ideas about what is being revealed, they agree on the idea of revelation - that the 'big' worldview questions need revelation if we are to ever find true answers.