This can be further broken down as
temporal perfection vs. eternal perfection
or simply
unbelief vs. faith
Liberals and the left are enflamed by faith in God or any deity...this is the "rift" between the Left and Islam and the Left may use Islam for a season to further its agenda but eventually that shaky alliance will end.
After all these muslims believe in a heaven or afterlife which is unacceptable to the godless Left.