I had always wondered if combat sports like boxing and MMA sinful? I know that MMA looks brutal on TV, but in reality, it is not as raw as it seems. No one in the UFC has gotten a bad injury that could of led to death. So is practicing such sports sinful?
Like many things, it would depend on the purpose. The Israelites practiced warfare at the direction of the Lord, which is definitely violent, but it wasn't done for entertainment. I used to do Tae Kwon Do, but I did it for exercise and to learn self-defense. What has to be watched for is chasing after a "sport" because you like watching people getting injured. Or worse, thinking that problems can be solved through violence. A qualification of an elder is a man who is not violent (I Timothy 3:3; Titus 1:7).
"A man of violence entices his neighbor and leads him in a way that is not good" (Proverbs 16:29).
"Keep me, O LORD, from the hands of the wicked; preserve me from violent men who have purposed to trip up my feet" (Psalms 140:4).
"Their feet run to evil, and they hasten to shed innocent blood; their thoughts are thoughts of iniquity, devastation and destruction are in their highways. They do not know the way of peace, and there is no justice in their tracks; they have made their paths crooked, whoever treads on them does not know peace" (Isaiah 59:7-8).
None of these are in the same category as a violent sport where two challengers compete under rules. But I hope you can see how such events can get out of hand with some people.