The orientation of Christian churches reflects the historically recorded idea of turning eastward to pray, as well as the architectural and liturgical premise that temples and churches should be built facing east (often specified as equinoctial east). The practice of facing churches west came about because that was the custom in Europe when many churches were constructed under the influence of Islam. Although this may not be true of all mosques, it is certainly true for most medieval ones. There are two main arguments for facing churches east: one based on theology and the other on architecture. The first argument comes from the book of Revelation where we are told to look for Jesus' return at dawning on the east. Because dawn comes from the east, Christians believe that God is sovereign over time and space, and so he could have Jesus return at any moment. Since churches should be ready to receive worshipers at a moment's notice, they should face east to catch people's attention as they arrive by foot or car. The second argument focuses on architecture and the influence of the sun on human life. Buildings reflect the light of the sun, so if a church is built with its front facing north or south, it will need to be repainted every few years to avoid having dark corners where sin can grow unchecked. Churches built with their fronts facing east are surrounded by light throughout the day and do not require repainting.