The whole work of salvation for sinners is a uniquely Trinitarian work. Consider the following passages:
THE FATHER ORDAINS THE WORK OF SALVATION
Salvation was His Plan.
When Jesus had spoken these words, he lifted up his eyes to heaven, and said, “Father, the hour has come; glorify your Son that the Son may glorify you, since you have given him authority over all flesh, to give eternal life to all whom you have given him… I glorified you on earth, having accomplished the work that you gave me to do…I have manifested your name to the people whom you gave me out of the world. Yours they were, and you gave them to me, and they have kept your word. Now they know that everything that you have given me is from you.”
He chose us and predestined us.
Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places, even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace, with which he has blessed us in the Beloved.
This was according to His wisdom and purpose.
…according to the riches of his grace, which he lavished upon us, in all wisdom and insight making known to us the mystery of his will, according to his purpose, which he set forth in Christ as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth. In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will
so that through the church the manifold wisdom of God might now be made known to the rulers and authorities in the heavenly places. This was according to the eternal purpose that he has realized in Christ Jesus our Lord
THE SON ACCOMPLISHED OUR SALVATION
He reconciled us.
More than that, we also rejoice in God through our Lord Jesus Christ, through whom we have now received reconciliation.
He redeemed us.
he entered once for all into the holy places, not by means of the blood of goats and calves but by means of his own blood, thus securing an eternal redemption.
We are adopted through Him.
For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!”
We are called into His fellowship.
God is faithful, by whom you were called into the fellowship of his Son, Jesus Christ our Lord.
(1 Corinthians 1:9)
We are justified by His work.
and are justified by his grace as a gift, through the redemption that is in Christ Jesus
Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God.
THE HOLY SPIRIT APPLIES THE WORK OF SALVATION TO THE CHURCH
He gives the new birth, renews, and regenerates us.
That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, ‘You must be born again.’
(John 3:6-7)he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit
He is the Helper Jesus sent.
Nevertheless, I tell you the truth: it is to your advantage that I go away, for if I do not go away, the Helper will not come to you. But if I go, I will send him to you.
He dwells within us.
Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body.
(1 Corinthians 6:19-20)
You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.
He conforms us into the image and likeness of Christ.
And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit.
(2 Corinthians 3:18)
He empowers us for Christian living.
But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law. And those who belong to Christ Jesus have crucified the flesh with its passions and desires.
that according to the riches of his glory he may grant you to be strengthened with power through his Spirit in your inner being, so that Christ may dwell in your hearts through faith—that you, being rooted and grounded in love, may have strength to comprehend with all the saints what is the breadth and length and height and depth, and to know the love of Christ that surpasses knowledge, that you may be filled with all the fullness of God.
Now to him who is able to do far more abundantly than all that we ask or think, according to the power at work within us, to him be glory in the church and in Christ Jesus throughout all generations, forever and ever. Amen.
He helps and intercedes.
Likewise the Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit himself intercedes for us with groanings too deep for words.
He keeps us to the very end.
And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ.