But Jesus said God wants love, not sacrifice. Sometimes love means sacrifice, but sacrifice doesn't necessarily mean love.
I was reading from St. John Bosco a few days ago and something reminded me of where we left this thread.
A quote from one of his dreams:
"A great mistake which boys make is that of thinking that penance must be practiced by sinners only. Penance is necessary also in order to preserve innocence. If St. Aloysius had not done penance, he would certainly have fallen into mortal sin. This should be continually preached, inculcated and taught to children. How many more would preserve their innocence, while at present there are so few!"
I've only come to understand recently (my cluelessness is a product of being a cradle N.O. Catholic

) that practicing penance is something we should do not only to atone for our sins, but to avoid future sinning as well. The regular denial of things which are not sinful prepares us for denying ourselves of things we desire which are sinful. The saints practiced tons of this! So, sacrifice as penance, especially when it is not demanded of us, is an excellent way to show love of God in maintaining the purity of our souls.