The Trinity and Salvation
It clearly belongs to the very essence of the gospel of salvation that, through the Lord Jesus Christ and the Holy Spirit, God has communicated himself to us in atoning propitiation and saving power. This is a threefold self-communication of God to us in unreserved love, in which the Father, the Son, and the Holy Spirit, while other than one another in the distinctiveness of their Persons and Acts, are perfectly and indivisibly one, for no divine Person is what he is apart from the others.
The Father is not properly Father apart from the Son and the Spirit, and the Son is not properly Son apart from the Father and the Spirit, and the Spirit is not properly Spirit apart from the Father and the Son. They are completely at one in their mutual indwelling, containing, and interpenetrating of one another. This triune relation between the Father, the Son, and the Holy Spirit applies to all their activity, not least in the movement of atoning propitiation and expiation whereby all who come to the Father through the Son and in the Holy Spirit are redeemed and saved from sin and death and judgment.
Thus belief in the Holy Trinity does not have to do simply with our knowledge of God as he is in his inner life and being, but with the very substance of the gospel of salvation ground in and flowing from the very love which God eternally is in himself. It is indeed God’s threefold giving of himself to us as Father, Son, and Holy Spirit that is our salvation. This is succinctly and beautifully expressed in the benediction: “The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Spirit, be with you all.” As such, devotion to one God as Father, Son, and Holy Spirit belongs to the inner structure of our Christian faith and worship, while the doctrine of the Unity and Trinity of God constitutes the fundamental grammar of Christian theology.
Thomas F. Torrance, from The Mediation of Christ
Thomas F. Torrance (1913-2007) was a Scottish Protestant theologian. He is generally acknowledged as one of the most significant theologians of the 20th century. His understanding of the Trinity and the greatness of the work of Christ has had a powerful influence on numerous theologians and pastors. Some of his better known works are The Trinitarian Faith: The Evangelical Theology of the Ancient Catholic Church, Atonement: The Person and Work of Christ, and Incarnation: The Person and Life of Christ.