"Sanctified by What?"

But now I am coming to you, and these things I speak in the world, that they may have my joy fulfilled in themselves. I have given them your word, and the world has hated them because they are not of the world, just as I am not of the world. I do not ask that you take them out of the world, but that you keep them from the evil one. They are not of the world, just as I am not of the world. Sanctify them in the truth; your word is truth. As you sent me into the world, so I have sent them into the world. And for their sake I consecrate myself, that they also may be sanctified in truth.