The purpose is not pleasure, nor is it even happiness. Rather, the purpose is to do important things.
This is specifically Christian because it is to do important things that God calls one to do. One figures out what God is calling one to do through the practice of discernment.
Why do important things that God calls one to do? Because God is able to see what’s really important.
It was only because Europeans believed in God as the Intelligent Designer of a rational universe that they pursued the secrets of creation. In the words of Johannes Kepler [(one of the most distinguished astronomers in the history of science)], “The chief aim of all investigations of the external world should be to discover the rational order and harmony imposed on it by God and which he revealed to us in the language of mathematics.” […] Perhaps the most remarkable aspect to the rise of science is that the early scientists not only searched for natural laws, confident that they existed, but they found them! It thus could be said that the proposition that the universe had an Intelligent Designer is the most fundamental of all scientific theories and that it has been successfully put to empirical tests again and again.” – Rodney Stark, Bearing False Witness (2016), p. 162
My guess is that Stark is probably correct, and that the standard story that Christianity stood in the way of the rise of science is just about the opposite of what actually happened.