21. In Jude 20, 21, Jude combines the Father, the Son, and the Holy Ghost: and faith, hope, and love.
      Keep yourselves--not in your own strength, but "in the love of God," that is, God's love to you and all His believing children, the only guarantee for their being kept safe. Man's need of watching is implied; at the same time he cannot keep himself, unless God in His love keep him.
      looking for--in hope.
      the mercy of our Lord Jesus Christ--to be fully manifested at His coming. Mercy is usually attributed to the Father: here to the Son; so entirely one are they.

JFB.