Man, the Bible teaches is a tri-partite being. He is body, soul, and spirit. Though it is rather hard to distinguish between the spirit and the soul sometimes, still the spirit is the highest part of our being. The Bible says at death, our spirit will return unto God who gave it. God is the creator of our spirit which distinguishes us from animals.
Animals have a soul.
It is also an example of security . Father, into thy hands I commend my spirit. It will be secure with thee, into thy hands. My, how wonderful it is to know about the strength of the hands of God and what God has said about them. My Father which gave them to me is greater than all and no man is able to pluck them out of my Father's hand .