From Andrew Murray's book "Holy in Christ"
O Lord! the alone Holy One, Thou hast called us to be holy, even as Thou art holy. Lord! how can we, unless Thou reveal to us Thy Holiness. Show us, we pray Thee, how Thou art holy, how holy Thou art, what Thy holiness is, that we may know how we are to be holy, how holy we are to be. And when the sight of Thy Holiness only shows us the more how unholy we are, teach us that Thou makest partakers of Thy own Holiness those who come to Thee for it.
O God! We come to Thee, the Holy One. It is in knowing and finding and having Thyself, that the soul finds Holiness. We do beseech Thee, as we now come to Thee, establish it in the thoughts of our heart, that the one object of Thy calling us, and of our coming to Thee, is Holiness. Thou wouldst have us like Thyself, partakers of Thy Holiness.
If ever our heart becomes afraid, as if it were too high, or rests content with a salvation less than Holiness, Blessed God! let us hear Thy voice calling again, Be holy, I am holy. Let that call be our motive and our strength, because faithful is He that calleth, who also will do it. Let that call mark our standard and our path; oh! let our life be such as Thou art able to make it.
Holy Father! I bow in lowly worship and silence before Thee. Let now Thine own voice sound in the depths of my heart calling me, Be holy, as I am holy.