Sacrifice without heart change is meaningless

Religion is all about sacrifice.  People think that by giving things up, God will find favor on them.  But that is not how it works.  We could never sacrifice enough to earn God's favor.  Some give sacrifices but their heart never changes.  God can't stand that.  The reality is that is that only one person could give enough sacrifice to make a difference in our lives.  God had to send his only son to die for our sins.  His sacrifice wasn't meaningless.  Not only that but because of His sacrifice, my heart is changed.