Happiness is your nature. It is not wrong to desire it. What is wrong is seeking it outside when it is inside.
Whatever is done lovingly, with righteous purity and with peace of mind, is a good action. Everything which is done with the stain of desire and with agitation filling the mind is classified as a bad action.
Grace is not something outside or you.. In fact, your very desire for grace is due to grace that is already working in you.