The next day he saw Jesus coming toward him, and said, “Behold, the Lamb of God, who takes away the sin of the world!"(John 1:29, ESV)
Charles Spurgeon is known to have once said this line while warming up his voice and testing the acoustics of the building, when a man who was standing outside of the room heard it, went immediately home and fell on his knees seeking forgiveness.
In a sense, this is what we are all to do, to point to the Lamb of God. Our individual ministries, like John the Baptist's, is to simply point to Him. Behold, means to look or to see. It is written as a command.