The Arabic word ibadah (عبادة) or ibada, usually translated "worship", is connected with related words literally meaning "Slavery", and has connotations of obedience, submission, and humility. In terms of Islam, ibadah is the ultimate obedience, the ultimate submission, and the ultimate humility to God along with the ultimate love for him. Muslims believe that ibadah is the reason for the existence of all humanity. That is, Muslims believe that all people exist only to worship God. Ibadah consequently means following Islamic beliefs and practices – its commands, prohibitions, the Halal, and the haram. For Muslims, ibadah is also something that comes from the heart, or sincerity, as a result of belief in Islam. Therefore, ibadah is something that can not be forced upon another person.
Some Muslims believe that in Islam all types of worship and prayers have been decided by Allah and his rusul (prophets), so there is no need to resort to reasoning things out (Ijtihad). According to this view of Islam the duty of humans is to follow and practise what Allah and his prophets have taught humanity, so there are no substitutions for ibadah.
Many devout Muslims perform their religious duties during all circumstances. One example is that of Sheikh Muszaphar Shukor, who practiced his Islamic obligations while an astronaut aboard the International Space Station.