It is sometimes necessary to cooperate with a person one does not like or agree with, in order to combat a common threat.

Alternative form of the enemy of my enemy is my friend

Indicating that one's close associates prove more adversarial than one's opponents.

Borrowed money should be paid back as soon as possible.

Two parties who have an enemy in common should join forces against it.

Alternative form of with friends like these who needs enemies?

The journey is often more important than the destination.

One should be on one's toes and alert of one's surroundings if malicious people are around, to ensure that they cannot wreak havoc in one's life.