In many sporting competitions (and other types of competition) people will pray to God for help. Would it be fair to call such help cheating if it were granted? Is it ethical to even ask for what would be an unfair advantage over an opposing side in what should be a purely human competition? The critics of performance enhancing drugs seem to say nothing on this issue.
I don't think that it's possible for God to cheat, even if he answered the competitor's prayer for victory. However, I agree with Richard Heck that there is something unseemly about praying for someone else's defeat (or misfortune). If we think about real conflicts, rather than sporting competitions, it is even more unseemly to suppose that God is on our side. Our enemies are just as sure that God is on their side. Many religious people think that they see God's handiwork in various events. However, I doubt if we can understand God's Providence. We should never underestimate God's subtlety. I realize that I shifted the question from whether you would have an unfair advantage if you appealed for God's help in winning a sporting contest, and the help was provided. I don't see grounds for thinking that there is an *ethical* problem, but as Richard Heck said, a prayer for victory may be religiously inappropriate.