To have a proper confidence in salvation, believers don’t need to muster up greater and great conviction. Instead, we need deeper insight into what salvation is. When we understand our salvation thoroughly enough, conviction and assurance take care of themselves. An adequate doctrine of salvation —a soteriology— needs to be located first of all in something outside of us, needs to be specific in giving content to salvation, and needs to be expansive enough to survey the full range of salvation.
My recommendation for a suitable location for the doctrine of assurance is in a soteriology that is elaborately and explicitly Trinitarian.
There is a lot that could be said about a trinitarian soteriology. Since my purpose here is only to show what it contributes to the proper placing of the doctrine of assurance, I will describe trinitarian soteriology as concisely as possible: God has brought about salvation by sending the eternal Son into our history as the incarnate Son, and the Father and Son together pour out the eternal Spirit as the Holy Spirit of Pentecost on the basis of Christ’s finished work. The missions of the Son and Spirit, which together constitute the history of salvation, are prolongations or temporal enactments of the eternal processions which constitute the triune being of God.
While a well-ordered soteriology will affirm that God is free by insisting that the temporal missions are not strictly necessary to God, it will also rejoice in tracing the way those missions are temporal expressions of God’s eternal being. God saves humans by being for them in time what he is in himself: Father, Son, and Holy Spirit. The gospel is anchored in the Trinity, and believers can sing “Anchored in Jehovah, I shall not be moved.” Assurance of salvation has its ultimate and most comprehensive doctrinal foundation in this Trinitarian soteriology, and only subsequently in the doctrinal locations usually urged in isolation.
Let us admit that, considered abstractly, God could have saved us many ways: by fiat, by annihilating and reconstituting us, by destroying evil, or by a thousand ways his omniscience could have devised. But the way of salvation that he chose involved sending the eternal son into human history, making the one who was always begotten of the Father into the one who was sent on a mission by the Father. Likewise, the Holy Spirit who always proceeds from the Father (and the Son) has come into our history on a mission to apply and perfect the work of the Son. We experience reconciliation when God as the Father puts the Spirit of the Son in our hearts.
In other words, God saves by being himself for us: turning the eternal processions outward into temporal missions, and bringing us into the power of those relationships. The gospel is God opening his triune life to us. This is a kind of soteriological maximalism: there is no higher blessing conceivable than this incorporative adoption into the life of God.
The presuppositions of this Trinitarian soteriology can be stated more precisely, in the following form: The temporal sending of the Son is the economic form of his eternal procession from the Father. Similarly, the temporal sending of the Spirit is the economic form —free, gracious, unexacted, but directly in line with and revelatory of—his eternal procession from the Father and the Son. The eternal processions are correlated to the temporal missions. These presuppositions were worked out helpfully by Augustine, but their most precise articulation comes in the work of Thomas Aquinas:
‘Mission’ denotes not just coming forth from an origin, but the terminus in time as well. A mission, therefore, takes place only in time. In other words, mission includes an eternal procession, but also adds something else, namely an effect in time; for the relationship of the divine person to an origin is eternal. We speak, therefore, of a twofold procession —the one during eternity, the other during time— in view of the doubling, not of relation to principle, but of the terminations —one in eternity, the other in time.
This Trinitarian soteriology builds on a clear distinction between and coordination of the immanent and economic Trinity, emphasizing the direct, personal, special, proper presence of the Son and Spirit as themselves among us as they are in eternity. The Son of God is the Son of God on earth as he is in heaven, opening up to us adoptive sonship on earth that is founded on the eternal sonship in heaven.
Here are some of the benefits of locating assurance within this explicitly Trinitarian context:
1. It ensures a greater objectivity than any other option. Back behind the economic sending of the Son and the Spirit, though in line with them, is the eternal immanent Trinity. The way this soteriology directs our attention to God’s absolute aseity, independence, and blessedness is unprecedented. And it does so without some of the distorting consequences of appealing first to God’s inscrutable sovereignty in election. It gets behind even that eternal counsel to the only thing which is behind the eternal counsel, the very bedrock of the being of God: his being as Father, Son, and Holy Spirit.
2. It takes the encounter between the believer and Jesus and puts it in the broader context of the Father, Son, and Spirit acting concertedly for each other’s glory, and then as a subordinate end, for our salvation. While a confession of the encounter between Jesus and me is integral to evangelical faith, it must happen against the horizon of Jesus and his Father. Trinitarian soteriology is intensely personal, but allows us to construe the word “personal” as an indication of the infinite depth of the divine life rather than as a pointer to my own richly developed inwardness in its religious manifestation. It enables believers to respond with proper gratitude to God’s action on our behalf, without degenerating into the “many-tongued but monotonous pro me, pro me, and similar possessive expressions” of an inwardly-focused piety.
3. This Trinitarian soteriology is routed through the economy of salvation, and moves from God to salvation history before contacting me and my own experience of salvation. This requires me to see my Christian experience as serving God’s larger ends, employing me as a witness to God’s spreading glory. The economic presences of the Son and the Spirit are, after all, missions, a word which was first of all a technical term in Trinitarian theology before it was a description of cross-cultural world evangelism. Our participation in the twofold mission of the Son and Spirit is not only our salvation but our employment in the mission of God. This keeps the quest for assurance from becoming selfish.