Run as fast as you can

The church is close, you observe its gothic stone walls covered by the mists. There is an open, sturdy iron fence between you and the church's doors. You hear zombies close to you.

The iron fence is rusty but functional and sturdy. Closing it would let you take your time to approach the church's doors, but you have to be fast and close it before the zombies arrive. Or you can leave the fence open, and run fast to the doors, trusting that you’ll reach them before the zombies catch you.