It is worthwhile for one to make an effort to achieve happiness. Just as the purpose of a plant is to grow, so it is that the main purpose of every human being is to survive and to grow until death.
The clash between science and religion has not shown that religion is false and science is true. It has shown that all systems of definition are relative to various purposes, and that none of them actually “grasp” reality.
The world is not looking for servants, there are plenty of these, but for masters, men who form their purposes and then carry them out, let the consequences be what they may.
Find the thing you want to do most intensely, make sure that’s it, and do it with all your might. If you live, well and good. If you die, well and good. Your purpose is done