Just because you cannot fight every evil does not mean you should fight no evils.
Secularism breeds narcissism. There is nothing higher to live for, so you live for you
The more passions you have the happier you'll be
If we weren't born with anti-social passions - narcissism, envy, lust, meanness, greed, hunger for power, just to name the more obvious - why the need for so many laws, whether religious or secular, that govern behavior?
Not everyone wants to be happy
Socialism values equality more than liberty.