and as Christ is the Head of the Church, not the Father or the holy Spirit: so he doth give life and sence to the body, and not the whole Trinity. If the speciall Offices of Christ be considered severally, much more if all of them be considered joyntly, it will evidently appeare, that both natures must necessarily concurre in the formall execution of them. For he cannot worthily performe the office of the chiefe Doctor of the whole Church, and heavenly Prophet, nor execute the office of an eternall high Priest, that is, offer a Sacrifice truly propitiatory, daily heare the prayers of all his people, and present them before God; nor exercise kingly power and authority in heaven and earth, who worketh to the forme of meere humanitie, or onely as he is man: When in those offices there must be a divine excellencie and efficacie.
Qualis substantia personae, talis & operatio, & qualis operatio, talis substantia.The end of personall union is the administration of his office; and the personall union of two natures in Christ had not been necessary, unlesse both had concurred as a formall beginning to that worke. For every agent necessarily worketh according to and by its forme; whence it followeth, either that the person of the Mediatour doth not consist of two natures, or both natures of Christ, as proper formes, doe necessarily concurre to the proper works of a Mediatour, because the proper operations must be conjoyned in one worke of a Mediatour, as both natures are joyned and united in one person. There is one God,1 Tim. 2.5,6. saith the Apostle, and one Mediatour between God and man, the man Christ Jesus: adding the man Christ, to shew that in him were both natures, that is, he was God and man in one person, and so a fit middle person or Mediatour. And man may be taken personally, not naturally, it being most usuall to name the whole person of Christ from either nature: as he is called the Lord of glory,1 Cor. 2.8. when his person is understood. And so in this place, the man Christ, that is, that person, who hath that nature by which he is truly called man:Iun, animad. in Bell. contr. l. 5. c. 3. not. 11,12. and of that appellation there may be divers weighty reasons more, amongst the rest this, that the Apostle would encourage us to put our trust and confidence in him as being our elder brother. By voluntary dispensation Christ is Mediatour as God incarnate, and not by nature as God. And according to that dispensation Christ is Mediatour to the Father, who is personally called God sometimes in this respect,Joh. 17.3. and 14.1. and distinguished from Christ as Mediatour:1 Joh. 2.1,2.and
