I hope to expound upon these questions at a later time. If you worship as an obligation, is it worship? If a sacrifice is given with a non-sacrificial attitude, is it a sacrifice?
I believe we do certain things based on faith and obedience; Tithing for instance. I also believe worship is a faith and obedience choice with an attitude of thanksgiving and praise. However obedience is not an obligation, but rather a faith response to the love of God and a craving to live in and experience God’s love. Therefore offering ourselves as living sacrifices (our spiritual act of worship) is out of love not obligation, duty, responsibility, or requirement. It’s like desert, everybody wants desert, but nobody ever has to eat desert.