If the bark is on, and your area is on the moist side the wood inside can start to rot before it dries. But, usually when you split it, it will dry. You will have a little reduced heating energy in such firewood, but it will still burn, and rotted stuff that has dried will burn too.
Can you buy firewood on the root here, I mean can you go to someone who has forest and ask if you can cut down some of his trees to clear up his forest, and pay a little fore it, and he get a job done too, and you get inexpensive firewood ?
Firewood is an amazing invention, it gives heat so many times. It warms you when you cut the tree down and chop it up. It warms you when loading it in the tractor trailer, or whatever you put it in, and it warms you when splitting it, and it warms you when stacking it, and it warms you carrying it inside, and then finaly it warms the entire house when you put it in the oven.
Bill