The Holy Spirit, Who is the Living Love between the Father and the Son is given to us as well, so that now we partake in that love. It is through this love, the Holy Spirit that we become like Christ.
If the Blessed Trinity lives in the just soul as in a temple,  a living temple of knowledge and love even while the just man lives on earth, how wondrously intimate must be this indwelling of the Blessed Trinity in the blessed who form the temple of heaven! .
This doctrine of the indwelling leads from the treatise on the Trinity to the treatise on grace. Grace is the created gift, brought forth and preserved in us by the Holy Spirit, who, by appropriation, is the Uncreated Gift, or by the Blessed Trinity, wholly present in us. Adoptive filiation, says St. Thomas,  comes to us, by appropriation, from the Father, who is the principle of natural filiation; but it comes also by the gift of the Holy Spirit, who is the love of the Father and the Son. The act of adoption by grace, he says elsewhere,  though it is common to the entire Trinity, is appropriated nevertheless to each person singly, to the Father as author, to the Son as exemplar, to the Holy Spirit as imprinting on us the likeness of that exemplar.
Grace, we may recall in conclusion, depends by its very nature on the divine nature common to all three persons; but, as merited for all redeemed souls, it depends on Christ the Redeemer.
Without Christ, without baptism, there is no Indwelling of the Holy Trinity.
If I had to teach only one thing for the rest of my life, it would be the truth and necessity of baptism.
It is through the graces of baptism that one comes to the experience of Christ the Incarnate One.
Souls are lost because of mortal sin which kills that life of God in us and through the lack of the acceptance of Christ as God and Man. Evangelization must be part of one's call, but if one is allowing God to perfect one, this call becomes one of being and not merely words.
to be continued...