Meaning and Purpose

For some theists, the question of the so called 'meaning of life' is related to the question 'what is my purpose'. This is because their idea of meaning is bound up with the fulfillment of god's plan.
The word 'purpose' has two distinct uses:

1) The purpose of a corkscrew is to open bottles. It was specifically designed to fulfil this purpose.

2)My purpose in opening the fridge was to get some chilled water to drink.

Some theists think that in order to have purpose in a truly meaningful sense, there has to be an overarching type 1 purpose that we have been specifically created by god in order to fulfill. My contention is that we can get along fine with type 2 purposes.

So, if we were made to fulfil some plan or higher purpose of god, would that in itself guarantee that our lives would be 'meaningful' in the sense that most people would recognise? Surely it might depend on what god's plan actually is? After all, if it emerged that god created us specifically to be food for a highly intelligent scavenging intergalactic species that were due to pass through our solar system soon, I imagine that there would be muttering in the pews.
The trouble is, Christians don't seem to be able to give us much in the way of a meaningful description of god's purpose.