You have got to be happy with how this turned out! Great job! Good luck with the contest!
If I was nitpicking, and this 100% comes down to opinion, I feel the vocal level is slightly to loud for the mix. Not by much...and again, opinion. Others may not feel that way at all. I'm coming from a background of jingles where the vocal HAS to be more prominent than it would be in a typical song. This seems slightly mixed that way.
Also, realize, I would typically never say a critique unless someone was asking, and even then, I typically don't respond. Because this means so much to you, and it's for a contest, I thought I would give my 2 cents. Let others weight in, and take it for what it's worth. With good intentions

Great vocal, great sound, great song! Be proud. You are serving God well with your talents!