Baptism into Christ's Body

I just started to read Robert Letham's Systematic Theology, published by Crossway in 2019. And it just might become my go-to one-volume systematic theology along with Louis Berkhof's. So far, it is riveting. (Never thought I'd say this about a contemporary systematics text!) I will probably post a bit more on it as I get into its contents more deeply, but for now I simply want to cite a portion on baptism.

As I began to read the section on baptism (in preparation for our daughter Zoe's baptism this upcoming weekend), I thought to myself, and blurted out to my wife: "This is my view! This is what the New Testament actually teaches!" It's rooted in the Bible's fairly straightforward teaching instead of our modern systems on these things, where baptism tends to get detached from its biblical, ecclesial, and salvific contexts. Letham does well in holding things together that few Christians (North American, at least) seem to be able to hold together.

Note that the discussion of baptism in Letham's volume comes after justification, not in a detached section on ecclesiology, but in a chapter entitled "The Beginning of the Christian Life," which is itself part of a larger section on "The Spirit of God and the People of God." Here's a salutary sample, and a good simple word on baptism:

It is appropriate to bring baptism into the equation at this point [after a discussion on justification]. The New Testament presents baptism as one of the points of entry into salvation, together with repentance, faith, and the reception of the Holy Spirit; these all feature in the evangelistic sermons in Acts. Throughout the New Testament Epistles there are allusions to baptism in this connection. Moreover, Rome makes baptism the instrumental cause of justification; while this has had unfortunate consequences, it alerts us to the need to provide some coherent answer. We saw in the previous chapter the close connections between regeneration, union with Christ, and baptism, connections often missed in evangelical and much recent Reformed thought [italics mine]. The Western world has been prone to thinking in analytical categories, breaking realities down into component parts, with distinctions to the forefront rather than connections. There is need to repair this imbalance in our present context. . . . 

Baptism is essential to the church's ministry. Jesus instituted it and required it as primary (Matt. 28:18–20). The way the church is to make the nations disciples is first by baptizing them. This occurred at Pentecost only a few days later (Acts 2:37–41). There, Peter linked baptism to the gift of the Spirit and cleansing from sin (1 Pet. 3:21). Paul also connects baptism with cleansing from sin (Acts 22:16) and elsewhere mentions baptism in the same breath as membership of the body of Christ and the gift of the Spirit (1 Cor. 12:13). It is the entry point into the church and so marks, in its way, the entrance into salvation. 

 —Robert Letham, Systematic Theology (Wheaton: Crossway, 2019), 705–706.