"Observe, then, that he calleth those saints whom here he describeth to be faithful ones in Christ; that is, faithful ones who are through faith united with Christ, so that he dwelleth in them and they in him... Observe then who are the true saints, viz. all who by faith are in Christ Jesus. Saints and faithful ones are carried as indifferent with the apostle, Col. i.2 and elsewhere. For though the formal effect of faith be not to sanctify, whence we are denominated saints, but to jnstify, whence we are called righteous, through forgiveness of sin and adoption unto life, yet faith effectually produceth our sanctification, whereupon we have the name of saints. Three things go to this: 1, the purifying of the heart; 2, the profession outward of holiness; 8, holy conversation." (p. 8)The root, Bayne says, is faith - that is what unites to Christ - and in the uniting comes the fruit, as the result of Christ's dwelling within. This distinction is critical - it is not the outward that unites to Christ, but the outward which shows and confirms the inward state of the heart. He who is united to Christ CANNOT continue in the way in which he once walked, unconcerned about Him and His ways. If our profession is that we are in Christ, then the truth of that profession can be gleaned by a changed life - not a perfect life, by any means, but one which is qualitatively different, and growing. Bayne continues,
"If you have learned Christ·as the truth is in..him, you have so learned him as to put off the old man and to put on the new. Faith worketh by love, even as a tree hath both his leaf and fruit. And as if a tree should be changed from one kind to another, the leaves and fruit should likewise be changed; as if a pear tree should be made an apple tree, it would have leaves and fruits agreeing to the change made in it; so man by faith having his heart purified, made a tree of righteousness, he hath his leaves and fruit; leaves of profession, fruit of action. So as sin a man, as a new tree set into and growing out of Christ, beareth a new fruit: he converseth in holiness and newness of life. Thus you see how those that are faithful are also saints, because by faith their heart is purified, their profession and conversation are sanctified; wherefore such believers who are mockers of saints, who will not be accounted saint holy, and such who are not changed into new creatures, walking in newness of life, they may well fear that their belief is not true, such as doth unite them with Christ; for whosoever is a true believer is a saint, whosoever is by faith in Christ is a new creature. We would be loath to take a slip or be deceived with false commodities in a twelve ponnd matter; let us be here no less diligent, that we take not an ungrounded, fruitless profession for a true faith, which resteth on God's word, made known, and is effectual to the sanctifying of the believer." (p. 9)The characteristic fruit of the believer is a growing fruit of righteousness - not perfection, for no man is perfect, save Christ. One reason, I think, why people dislike the name "saint" for those who profess Christ, is because they believe somehow that "saint" implies a prideful attachment to assumed perfection in one's life. We don't want to associate ourselves with something that doesnt' describe our current state of sanctification.... but indeed, "saint" is appropriate, for we are justified in Christ - and we are in Him, and because we are in Him we are growing, if slowly, haltingly, imperfectly. We should grasp hold of the name "saint", because it is not WE who make ourselves so, but Christ!
Eschewing that name, I think, gives us an excuse - an excuse to be lazy, to pay no regard to sin in our lives, to make no effort to cleanse our conversation (meant in the old Puritan way of conversation - the entirety of the Christian walk), because we know this side of glory we shall not be perfect. We are so prone be lazy - so prone to wander - so prone NOT to want to do the hard heart-work Scripture calls us to.
On the other hand, grasping that name and identity, and recognizing who we are in Christ, I believe, is supreme motive to walk in our Saviour's footsteps and seek renovation of heart and life, for we know it pleases the Lord who died for us and the Father who renews us by His spirit daily. Grasping that name and identity, we readily turn to the Word of God for meat and drink. Grasping that name and identity, we humbly admit our failings and confess them before our God and Father. If the Word is our meat and drink, if confession and repentance are ready upon our hearts and lips, and if we know in Whom we believe... that fruit will come. Christ has guaranteed it. The Apostle has encouraged us by it. The most High God will be vindicated through it all as the world sees Christ's sheep sanctified and being sanctified by His Spirit's work in them.