“Abu ‘Abd Allah (a.s.) has said, ‘There are three kinds of worship: there are people who worship Allah, the Most Majestic, the Most Holy, because of fear. This kind of worship is the worship of slaves. There are people who worship Allah, the Most Blessed, the Most High, for His rewards. This is the worship of people for hire. There are people who worship Allah, the Most Majestic, the Most Holy, for His love. This is the worship of free people and this is the best kind of worship.’”