The eunuch's confession
Whether the eunuch's creedal answer belongs to Luke's text or to a later hand.
Acts 8:36-38
36As they went on the way, they came to some water, and the eunuch said, “Behold, here is water. What is keeping me from being baptized?”
Verse 37 — the World English Bible omits this verse; the numbered slot is kept empty rather than filled from another edition.
38He commanded the chariot to stand still, and they both went down into the water, both Philip and the eunuch, and he baptized him.
What each tradition says
Rabbinic / Midrashic
No sourced position found. Checked the Jewish Encyclopedia (1905): art. "Baptism" (id 2456) and searches on the eunuch of Candace - the article treats Christian baptism only as a development from proselyte immersion; no statement on the textual status of Acts viii. 37 found.
Patristic
Augustine recounts that the eunuch believed on Christ. When they came to water, the eunuch asked who hindered him from being baptized. Philip asked if he believed on Jesus Christ, and the eunuch answered, "I believe that Jesus Christ is the Son of God."
Augustine of Hippo, Sermons on Selected Lessons of the New Testament (NPNF1-06) — Sermon XLIX [XCIX Ben.], § 11 (on the baptism of the eunuch)
Catholic
According to Haydock, Scripture often mentions one disposition while supposing others no less necessary. Here, with believing, sorrow for sins, firm hope, and love of God are also supposed.
George Leo Haydock, George Haydock's Catholic Bible Commentary (1859) — Comment on Acts viii. 37
Orthodox
No sourced position found. Checked Chrysostom, Homilies on the Acts of the Apostles (NPNF1-11): the homily on Acts viii. 26-40 passes from v. 36 to v. 38 without expounding v. 37; Cyril of Jerusalem (NPNF2-07, catechesis on baptism) and Gregory Nazianzen (Oration XL, On Holy Baptism) quote only Acts viii. 36; Synod of Jerusalem (Robertson 1899) - no statement on Acts viii. 37's authenticity found.
Reformed / Protestant
Calvin draws a general rule from the eunuch’s confession: baptism follows a profession of faith. Those estranged from the church must first testify that they believe in Christ before being received into it.
John Calvin, Commentary on the Acts of the Apostles, Volume 1 (Calvin Translation Society) — Comment on Acts viii. 37
Evangelical
Albert Barnes notes that this verse is missing in a very large number of manuscripts and has been rejected by many of the ablest critics. It is also omitted in the Syriac and Ethiopic versions. Barnes says it is hard to conceive why it was omitted in almost all Greek manuscripts unless it is spurious.
Albert Barnes, Albert Barnes' Bible Commentary (Notes on the New Testament) — Note on Acts viii. 37