The Old Testament ritual had one sacrifice which carried this truth in it. It is the first prescribed in the Book of Leviticus, the ceremonial book--namely, the burnt offering. Its especial meaning was this, that the whole man is to be laid upon God's altar and there consumed in the fire of a divine love. It began with expiation, as all sacrifices must, and on the footing of expiation there followed the transformation, by the fire of God, from gross earthliness into vapour and odour which went up in wreaths of fragrance acceptable to God. So _we_ are to be laid upon the divine altar. So, because we have been accepted in the Beloved, and have received the atonement for our sins through His great sacrifice, we are to be consecrated to His service and, touched by the fire which He sends down, we are to be changed into a sweet odour acceptable to Him as were 'the saints which are in Ephesus.'
II. Further, Christian men are saints because they are believers.
'The saints' and 'the faithful' are not two sets of people, but one. The Apostle starts, as it were, on the surface, and goes down; takes off the uppermost layer and lets us see what is below it; begins with the flowers or the fruit, and then carries us to the root. The saints are saints because they are first of all faithful. 'Faithful' here, of course, does not mean, as it usually does in our ordinary language, 'true' and 'trusty,' 'reliable' and 'keeping our word,' but it means simply 'believing'; having faith, not in the sense of _fidelity_, but in the sense of _trust_.
So, then, here is Paul's notion--and it is not only Paul's notion, it is God's truth--that the only way by which a man ever comes to realise that he belongs to God, and to yield himself in glad surrender to His uses, and so to become pure and holy like Him whom He loves and aspires to, is by humble faith in Jesus Christ. If you want to talk in theological terminology, sanctification follows upon faith. It is when we believe and trust in Jesus Christ that all the great motives begin to tell upon life and heart, which deliver us from our selfishness, which bind us to God, which make it a joy to do anything for His service, which kindle in our hearts the flame of fructifying and consecrating and transforming love. Faith, the simple reliance of a desperate and therefore trusting heart upon Jesus Christ for all that it needs, is the foundation of the loftiest elevation and attainment of the Christian character. We begin down there that we may set the shining topstone of 'Holiness to the Lord' upon the heaven-pointing summit of our lives.
Note how here Paul sets forth the object of our faith and the blessedness of it. I do not think I am forcing too much meaning into his words when I ask you to notice with what distinct emphasis and intentional fulness he employs the double name of our Lord here to describe the object upon which our faith fixes, 'Faithful in _Christ Jesus_.' We must lay hold of the Manhood, and we must lay hold of the office. We must rest our soul's salvation on Him as our brother, Jesus who was incarnate in sinful flesh for us; and we must also rest it on Him as God's anointed, who came in human flesh to fulfil the divine loving-kindness and purposes, and in that flesh to die. A faith in a Jesus who was not a Christ would not sanctify; a faith in a Christ who is not Jesus would be impalpable and impotent. We must take the two together, believing and feeling that we lay hold upon a loving Man, 'bone of our bone and flesh of our flesh'; and also upon Him who in His very humanity is the Messenger and Angel of God's covenant; the Christ for whom the way has been being prepared from the beginning, and who has come to fulfil all the purposes of the divine heart.