Events beyond any civilization's control

God

Most Christian perspectives expect an end of this world. We should not bring it about ourselves (e.g., Gen. 24:2, Mt 24:36).

Science

The sun is expected to consume the earth in about 5 billion years. An expected collision of our "milky way" galaxy with another (the Andromeda Nebula) in about 3 - 4 billion years may be a threat (it could be an opportunity).

There seems to be a limit to life in the universe. As far as science understands the world, intelligent life requires the processing of information, which requires an increase of entropy and thus further equalization of differences. The universe does not seem to allow for intelligent life indefinitely, as eventually everything is expected to become equally cold and any remaining sources of differences would become incrementally smaller. That prospect is very far off, the last black holes are only expected to evaporate after on the order of 10 to the 100 years.

With regards to science, it seems more effective to focus on the issues within one's control.