It is Satan's nature to pursue his evil activities, right up until the day that Christ returns. Indeed Revelation 12:12 says, "Therefore rejoice, you heavens and you who dwell in them!  But woe to the earth and the sea, because the devil has gone down to you!  He is filled with fury, because he knows that his time is short."  He does most of his evil work through people who believe that his lies are the truth: people who want the benefits he promises, not knowing that Satan only delivers destruction (John 10:10).    

Part of the devil's terminal evil work is to invent substitute messiahs who claim to be saviours.  There will be no shortage of experts, purveying false spirituality, and they will try to invade and seduce the churches (1 Timothy 4:1).  Even some who would consider themselves Christians may be led astray; as will some church leaders.  The false prophets will all have some popular appeal and will be promoted by earnest advocates with apparently good credentials.  They may apparently demonstrate supernatural powers and capture the hearts and minds of their targets (2 Thessalonians 2:9-12).  

Jesus now brings us the third 'be on your guard/watch' of this chapter (Mark 13:5, 9, 23).  As before, it is not a personal security alert - like an air raid siren urging us to take cover: it is the need to guard ourselves, lest our gullibility and sentimentality about religion leaves us open to believe what is false about God's Son, and make people believe that other people or ideas are superior to Jesus.  One of Jesus' final instructions to His disciples, as He was being attacked by the Enemy, was, "Watch and pray so that you will not fall into temptation. The spirit is willing, but the flesh is weak." (Mark 14:38).  That command is for us in the Last Days, too.  What should we watch?  We must watch the Word and the world at the same time – comparing what God says with the voices of our age.  How do we pray?  For discerning eyes and courageous hearts to last the course with Jesus.  And we need to be continually vigilant (1 Peter 5:8).  The believers, leaders or churches that assume they are immune from enemy attack are the ones most easily brought down (2 Timothy 2:15-18).

A good start is important in every race, but a good finish is essential.  Paul's question reinforces this in Galatians 5:7 - You were running a good race.  Who cut in on you to keep you from obeying the truth?  The Bible is our only objective reference point, and the church discards it at its peril - even eternal peril.  Whatever the trendy theologians may say, stick to God's Word, and let the Jesus who died for you lead you safely home.  Then we can pray honestly and in open reliance on the only Saviour who is true and our guarded heart and mind will be the source of our confident witness to what is true.