(CG 4/20). Of the Effects which the Scriptures attribute to the Holy Ghost?... (Book 4. God, in His Revelation) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

SINCE the Father, Son and Holy Ghost have the same power, as they have the same essence, everything that God works in us must be by the efficient causation of Father, Son and Holy Ghost together. But the word of wisdom, sent us by God, whereby we know God, is properly representative of the Son; and the love, wherewith we love God, is properly representative of the Holy Ghost. Thus the charity that is in us, though it is the effect of Father, Son and Holy Ghost, is in a certain special aspect said to be in us through the Holy Ghost. But since divine effects not only begin by divine operation, but are also sustained in being by the same, and nothing operates where it is not, it needs must follow that wherever there is any effect wrought by God, there is God Himself who works it. Hence, since the charity wherewith we love God is in us through the Holy Ghost, the Holy Ghost Himself must be in us, so long as charity is in us. Know ye not that ye are the temple of God, and the Holy Ghost dwelleth in you? (1 Cor. iii, 16.) And through the Holy Ghost the Father and Son also dwell in us. Hence the Lord says: We will come to him, and take up our abode with him (John xiv, 23). Cf. 1 John iv, 13, 16.

It is a point of friendship to reveal one's secrets to one's friend: for as friendship unites affections, and makes of two as it were one heart, a man may well seem not to have uttered beyond his own heart what he has revealed to his friend. Hence the Lord says to His disciples: I will not call you servants, but friends, because all things that I have heard from my Father I have made known to you (John xv, 15). Since then by the Holy Ghost we are constituted friends of God, the revelation of divine mysteries to men is fittingly said to take place through the Holy Ghost: To us God has revealed them through the Holy Ghost (1 Cor. ii, 10). Besides the revealing of one's secrets to one's friend, which is part of the union of affections that goes with friendship, there is a further requisite of the same union, to share one's possessions with one's friend, according to 1 John iii, 17. And therefore all the gifts of God are said to be given us by the Holy Ghost (1 Cor. xii, 7-11). And by such gifts of the Spirit we are conformed to God, and by Him rendered apt to the performance of good works, and our way is thereby paved to happiness: which three effects the Apostle declares: God hasanointed us, and sealed us, and given the pledge of the Spirit in our hearts (2 Cor. i, 21, 22: cf. Eph. i, 13, 14). The sealing may be taken to imply the likeness of conformity to God: the annointing, the fitting of man to do perfect acts: the pledge, the hope whereby we are set on the way to the heavenly inheritance of life everlasting.

And because good will towards a person leads at times to the adoption of him as a son, that so the inheritance may belong to him, the adoption of the sons of God is properly attributed to the Holy Ghost: Ye have received the spirit of adoption of sons, wherein we cry, Abba, Father (Rom. viii, 15).

Again, by admission to friendship all offence is removed. Since then we are rendered sons of God through the Holy Ghost, through Him also our sins are forgiven us by God; and therefore the Lord says: Receive ye the Holy Ghost: whose sins ye shall forgive, they are forgiven them (John xx, 22). And therefore forgiveness is denied to them who blaspheme against the Holy Ghost (Matt. xii, 31), as to persons who have not that whereby man attains the forgiveness of his sins.