There's a lot to admire in this picture and I'm going with what you have already been told. I think Ken Kruse put it very well when he said that you did nothing wrong but you haven't realised the shot's full potential. If you don't have Photoshop or similar software may I suggest that you download a programme called Gimp - it's like a basic form of Photoshop and it's free. You will find plenty of tutorials on Youtube to help you get to know it and I think you will be amazed at how much you can improve pictures when you get to grips with even the most rudimentary of editing techniques.
With regards to how I think you could improve the picture I would suggest that, apart from the lightening of the low-lights, the image could do with a bit of cropping. The church is right in the centre of the frame which takes out some of the energy from the image and with that in mind I would crop out some of the water at the bottom - maybe a quarter of the total height of the photo - and then remove a half to two-thirds of the large tree on the left.
All criticisms aside, I think you have a very pleasing, atmospheric shot which suggests to me that you have a good eye. Keep up the good work!