Honda odyssey keeps turing off?

I have a 2006 Honda Odyssey and it keeps turning off as if there's no battery left. I'm thinking thats what it is because it will turn on one day and then the next day it won't? And also the left door won't cloes its an automatic door closer so i don't even know what it could be. The car has about 94k miles so its pretty good. I've never had this problem with this car but i need it fix as soon as possible

Could be battery post are corroded, check battery and see if there's a lot of gray looking matter on the battery post if so you can remove post clean with a solution of baking soda and water then reinstall. You could loose some of your radio settings etc. And will have to reprogram them.