I have never cared for modern churches because they seem to lack any historical root, especially in the US. Here is a modern design that seems to defy my negative point of view.
Temppeliaukio Church was built in 1968-1969. It was designed by the architect brothers, Timo and Tuomo Suomalainen. The church is built into solid rock, therefore, it is also known as the Church of the Rock. Natural light brightens the inside through 180 glasses between the dome and the wall. The church is often used for concerts, because of the excellent acoustics. Temppeliaukio Church is one of the most famous tourist attractions in Helsinki.