There are two categories of sin: sins against God and sins against man. By default, every sin is against God. Yet, not all sin is against man.
Why would the Lord invite those weary from labour to wear a yoke? And then, why would the Lord promise rest by inviting people to labour?
Many people use time set aside for rest to do things that deprive of rest. This compounds the need for rest and the problems associated with not getting any.
