Today's reading Mark9:14 - Luke 1:80
"And what I say unto you I say unto all, Watch." Mark 13:37 KJB
Jesus was speaking to a few of the disciples about what they should expect to happen. A lot of fighting and persecution will happen. There will be signs to look for that should not surprise them. They will need to pay attention. They will need to watch.
Even today, two thousand years later, we also need to pay attention and keep our focus on what God has for us to do. The goal is to spread the gospel to every nation (13:10). So if we keep that as the most important thing then the other things might not so easily distract us.