Aw well pete. Look at it like this.

The observable and deduceable happens regardless of belief.

Two thousand years from now, the superstitious, if evolution hasn't kicked in and the need for it no longer applies, will possibly be getting their moral compass from the good book.

The church of the glory of Gandalf will be shunning the reformed poor Congregational church of Samwise. Meanwhile, there will be those practicing the dark arts of Mordor... Those who kick the bucket will be queuing at the Grey Havens quayside and the best way to lead an enchanted life will be if you are lucky to be short in height with hairy feet.

Yet strangely, f will still equal ma.