10 And the disciples asked him, "Then why do the scribes say that first Eli'jah must come?" 11 He replied, "Eli'jah does come, and he is to restore all things; 12 but I tell you that Eli'jah has already come, and they did not know him, but did to him whatever they pleased. So also the Son of man will suffer at their hands." 13 Then the disciples understood that he was speaking to them of John the Baptist.
God gives signs to show what he is about to do. John the Baptist is one such sign, who pointed to Jesus and prepared the way for his coming.
John fulfilled the essential task of all the prophets: to be fingers pointing to Christ. John is the last and greatest prophet of the old kingdom, the old covenant.
The Jews expected that when the Messiah would come, Elijah would appear to announce his presence. John fills the role of Elijah and prepares the way for the coming of Christ by preaching a baptism of repentance and renewal.
As watchful servants, we, too must prepare for the Lord's coming again by turning away from sin and from everything that would keep us from pursuing his will.
Are you eager to do God's will and are you prepared to meet the Lord Jesus when he returns in glory?