Some Muslims prefer the use of reversion rather than conversion, because Muslims believe that all people are born Muslims. Our parents and society are what make us choose other religions. We believe people are born in a state of fitrah. Fitrah is our natural tendency to believe in one God. Consequently, by embracing Islam, you return to your natural disposition.
Certainly, our newfound belief in Islam is a change, but the change may seem very easy and smooth because of our natural inclination that leads us in that direction. All other creation follow the natural laws put forth by the Creator, which is Islam, or submission. Islam is the natural religion, but humans can choose to disobey. The human is the only creation with free will. Each of us has to constantly decide whether or not we will be a servant of our Creator through our beliefs and actions. The Prophets were all Muslims, and today we as Muslims submit to our Creator through our understanding of Islam from the last Prophet and Messenger PBUH. That is the essense of the Islamic testimony of faith, or shahada.
How Allah Found Me in Texas
"This day, I have perfected your religion for you, completed My favor upon you, and have chosen for you Islam as your religion." - Quran 5:4.