Sings of the end(s)

In Matthew 24 and 25 the disciples ask Jesus how they will know the end is near, and when Jesus will return.  He gives them two answers.  He speaks about the destruction of Jerusalem and then goes on to the end of time when He will return.  He tells them to be careful and watch for His return.  The words that He used then for them ring so true for us today.  We are closer to His return than at any other time in history.  How will He find us when He returns?