It can't hit or see you so it resists the attacks. Give it the ability to hit you and it'll stop resisting.
Clever....I like the idea to go to the Nether to block it's ability to fly high. Yes use loads of TNT light the place up!!!!!
You cannot trap a Wither in bedrock and kill it. You need to fight fair as it were; If it cannot see a way to attack you, you cannot hurt it.
Thanks for responses! I was just curious if something changed because I have done this before. I will try all of the suggestions
Play some calming music and let it drift to sleep...Then pounce at it like a lion, stabbing it repeatedly with your sword.
TNT would slice through the netherrack like butter. Then before you know the precious star is lost to the lava gods...
I made a public Wither kill chamber with a viewing area for those who don't wish to get hurt but wanna see the wither go down. Has been tested and tried. Works like a Charm. I even kill the wither for you and you get the star, provided you bring the skulls needed. However I suggest you replace the nether rack with something much stronger. You may have to make it lower to get him out. If you attacked him with a diff higher than 1 switching back to 1 will not work. I kill these things when they are wild and running amok. It takes longer but can be done.
I made a smite sword and whne i came back he was suffocating in the roof. Smite put the icing on the cake and easily killed it! Thanks for everyone's help! I love how i thought 7 tnt would help me xD