Thank you for the insights you have provided on the topic of Baptism. While I am still digesting what you have put together, and while you have a busy week, I wanted to respond to your question on my definition of what Baptism is. I will also provide a helpful summary of the four (4) different views on Baptism I found in Hayford's Bible Handbook.
Your short definition of Baptism is as follows: "baptism is an outward act that represents the inward reality of God's grace received." And so, if I may try to clarify the issue, you see Baptism as a wholly human act of obedience with this action being symbolic of the inward act and working of God.
Here is where the Lutheran definition of Baptism differs with your definition (this definition is from my Reformation Study Bible) – Lutherans and those of the Reformed faith view Baptism as a sign from God that signifies the inward cleansing and remission of sins (Acts 22:16, 1 Cor. 6:11, Eph. 5:25-27). Baptism is Spirit-wrought regeneration and new life (Titus 3:5), and the abiding presence of the Holy Spirit as God's seal testifying and guaranteeing that one will be kept safe in Christ forever (1 Corinthians 12:13, Ephesians 1:13-14). And so, this is the fundamental difference of our two positions – you view Baptism as merely a human act, while the Traditional view of Baptism is that it is from God.
And so, I hope this brings to your mind Jesus' question to the chief priests and elders when He asked them "The baptism of John, from where did it come? From heaven or from man?" (Matthew 21:25, Mark 11:30, Luke 20:4). This story reveals Jesus' authority as coming directly from God. As well as confirming that John's Baptism of Repentance is from heaven and not from man. And of course, this means that the New Testament of Believer's being Baptized into Christ is also from God and not man. This is all from God, and so again I think the Lutheran view of Baptism as coming from God, and not merely a human "symbolic" action is the best Biblical view.
I hope the following summary of the four main views of Baptism from Hayford's Bible Handbook is helpful:
The nature of baptism. Four positions on the nature of baptism and the early church's practice (Acts 2:41; 8:12, 36-39; 9:18; 10:48, etc.) exist among Christian groups.
The sacramental view—According to this belief, baptism is a means by which God conveys grace. By undergoing this rite, the person baptized receives remission of sins, and is regenerated or given a new nature and an awakened or strengthened faith. Both Roman Catholics and Lutherans have this view of the nature of baptism, born of their interpretation of John 3:5.
The traditional Roman Catholic belief emphasizes the rite itself—that the power to convey grace is contained within administration of the sacrament of baptism. The Lutheran view concentrates on the faith that is present in the person being baptized; awakened faith due to the preaching of the Word of God.
The convenantal view—Some other Christian groups view baptism as a sign and seal of God's covenant, or God's pledge to save man. That is, because of what He has done and what He has promised, God forgives and regenerates. Thus, on the one hand, baptism is a sign of the covenant; on the other, it is the means by which people enter into that covenant and its benefits are obtained.
In the covenantal view, baptism serves the same purpose for New Testament believers that circumcision did for Old Testament believers, these two procedures being linked in Colossians 2:11-12.
The symbolical view—This view stresses the symbolic nature of baptism by emphasizing that baptism does not cause an inward change or alter a person's relationship to God in any way, but is a token or outward indication of an inner change already occurred in the believer's life. It serves as a public testimony.
This position explains that the church practices baptism and the believer submits to it because Jesus commanded that this be done and He gave us the example by being baptized Himself. Thus, baptism is an act of obedience, commitment, and proclamation (Matt. 28:18-20; Mark 16:15, 16).
The dynamic view—Increasing numbers of Christians see elements of truth in other viewpoints, but find their focus on the power (dynamic) inherent in the Holy Spirit's presence at baptism. While repentance and faith must precede the moment, and new birth has been experienced, water baptism is seen as a moment (1) at which a breaking of past bonds to sin may be severed, as Israel's oppressors were defeated—1 Cor. 10:2; (2) when a commitment to separate from the past life of carnal indulgence is made, as circumcision symbolized—Col. 2:11-15; and (3) when the fullness or overflowing of the Holy Spirit's power may be added to enhance the believer's power for witness and ministering (Acts 2:38, 39). This position sees baptism as both a witness and as an encounter. It is symbolic (burial to the past—Rom. 6:3-4) but it is also releasing and empowering for the future.
And so, Lutherans hold to the Sacramental View of Baptism, while Bryan I believe you hold to the 'Symbolic' view. If this is incorrect, please let us know. Otherwise, I will continue looking at the information you have provided, and I hope to have more for you on especially Infant Baptism later on. Yes, I have heard your teaching me about the Great Commission, and I will try and make sure I properly use it in my future posts - J. /s/Tom