Those who are addressed are, in the first place, "all the saints in Christ Jesus who are at Philippi." The saints, or holy ones, is a common expression in the Scriptures. The word "sanctify" is applied both to persons and to things. Bible-readers will have noticed that the term seems to vibrate or vacillate between two meanings,--signifying on the one hand the production of personal intrinsic holiness, and on the other merely consecration, or setting apart of anything to God's service. Now the connection of both meanings will appear, if we mark how both meet in the word as it is applied to the children of God. For such are separated, set apart for God from sin and from the world; not, however, by a mere outward destination, devoting them to a certain use and service, but by an internal hallowing, which makes the man really in his inward nature holy, fit for God's service and God's fellowship. This is done by the regeneration of the Spirit, and by His indwelling thereafter. Hence, to distinguish this consecration from the mere outward ceremonial sanctification, which was so temporary and shadowy, we find the Apostle Peter (i. 2) saying that God's children are chosen "by sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus." For the ancient Israel was sanctified to obedience in another manner (Exod. xxiv. 6).
Now because this real consecration takes place when we are grafted into Christ by faith, because the Spirit comes to us and abides in us as the Spirit of Christ, because whatever the Spirit does, as our Sanctifier, has its rise from Christ's redeeming work, because He unites us to Christ and enables us to cleave to Christ and hold fellowship with Him, therefore those who are thus sanctified are called saints _in_ Jesus Christ. It is the Spirit who sanctifies; but He does so inasmuch as He roots us _in_ Christ and builds us up in Christ. Therefore saints are sanctified _by_, or _of_, the Spirit; but they are sanctified (or holy) _in_ Christ Jesus.
This expression, "saints," or some phrase that is equivalent, occurs commonly in the Epistles as the designation of the parties addressed. And two things are to be observed in connection with it. _First_, when the Apostle addresses "all the saints," in any Epistle, he is not shutting out any professed members of the Church, any professed believers in the Lord. He never speaks at the outset of an Epistle as if he meant to make deliberate distinction between two several classes of members of the Church: as who should say, "I write now to some part of the Church, viz., the saints; as for the rest, I do not now address them." Hence we find the term used as equivalent to the Church--"to the Church of God which is at Corinth, with all the saints which are in all Achaia," and again "to them ... that are called to be saints." We shall see presently the lesson which this is fitted to teach. But, _secondly_, on the other hand, the Apostle's use of the word makes it clear that he uses it in the full sense which we have explained, of a real saintship. He does not restrain the sense to some merely external saintship, as if his meaning were "professing Christians whether they are real or not." The word stands, in the inscriptions, as equivalent to "sanctified in Christ Jesus," "faithful in Christ Jesus," "beloved of God"; or as in 2 Peter i., "them that have obtained like precious faith with us," and in 1 Peter, "Elect according to the foreknowledge of God unto obedience." Thus then we are to take it:--The Apostle wrote to the visible, or the professed and accepted followers of the Lord, on the understanding that they were what they professed to be. He was not to question it: he assumed that they were saints of God, for to profess the faith of Christ is to claim that character. He rejoiced to hope that it would prove to be so, and gladly took note of everything which tended to assure him that their holiness was real. He proclaims to them, in the character of saints, the privileges and the obligations that pertain to saints. It was the business of every man to look well to the reality of his faith, and to try the grounds on which he took his place with those addressed as beloved of God and called to be saints. There might be some who had but a name to live (2 Cor. xiii. 5). If so, it was not the Apostle's part, writing to the Church, to allow that possibility to confuse or lower the style of his address to Christ's Church. He wrote to all the saints in Christ Jesus who were at Philippi.