Before Adam and Eve sinned, they were two happy, naked vegetarians. Immediately after eating the fruit God commanded them not to eat, they were naked and ashamed. In an effort to cover their shame, they sewed fig leaves together. When God found them in the garden, He slaughtered the first animal in history to make skins to cover Adam and Eve.
In the first sin we see man making an effort to cover his own transgression. God makes it clear that man’s efforts are not sufficient to cover sin. We also see that the shedding of blood is required to forgive sins (see Heb. 9:22).
The first animals that were ever butchered were killed by God Himself. This is our first shadowy picture of Jesus Christ, shedding His blood for the sins of mankind.
Adapted from Don’t Stub Your Toe by Todd Friel
Genesis 3:21 Also for Adam and his wife the Lord God made tunics of skin, and clothed them.
Ray Comfort's Daily Evidence 
We also see that the shedding of blood is required to forgive sins
Why? surely God is all powerful and can do all things. Can’t he forgive without spilling blood
I would also say that the covering provided by God is proof that Adam and Eve not only repented but believed God could atone for their sins. These coverings received are proof they were believers!
How do I reply to Wrong Again Ray’s wacky ideas?
Here’s a few problems for Wrong Again.
1) Sin may be defined as someone forming the intent to do a thing they know is wrong.
Intent is the key. You can’t break a law or sin accidentally you have to do it intentionally.
Trouble is until Adam & Eve ate of the tree of knowledge of good & evil they had no idea what evil was. Since Adam & Eve had no idea what evil was they couldn’t have intended to perform an evil deed.
Second problem. According to Ray the animals that God killed were like Jesus.
1) God could have just created some clothes through a miracle. Could God have forgiven us through a miracle? Adam & Eve wore the skins of the animals. Does Ray really believe that Christians skin and wear Jesus? That’s blasphemous Ray.
I think your church should really look at the implications of what you believe.