Acts 8:38

And he commanded the chariot to stand still: and they both went down into the water, both Philip and the eunuch; and he baptized him. And when they came up out of the water, the Spirit of the Lord caught away Philip; and the eunuch saw him no more, for he went on his way rejoicing.

Under Acts 8:31, it was noted that the eunuch did no less than seven things in the discharge of his duty to be concerned about his own salvation; and here it is clear that he did three additional things. He requested baptism, commanded the chariot to stand still, and submitted to baptism. There are many today who need to command their own chariot to stand still while they submit to the ordinance of God.

Down into the water ... up out of the water ... No man could frame a sentence in any language that would show any more conclusively than does this one that the baptism here administered was by immersion. The type of comment that can deny immersion here is fraudulent.

Went on his way rejoicing ... Throughout the book of Acts, Luke brings into view the "joy" and the "rejoicing" of those who obeyed the gospel. Significantly, the rejoicing came after the baptism here, as it does elsewhere. One grand purpose of this book is to reveal how men become Christians; and, taken collectively, the various conversions in Acts reveal one plan of salvation and one alone. Invariably, those who were saved:

They heard the word of God.

They believed what was preached.

They believed on the Lord Jesus Christ.

They repented of their sins.

They confessed the Saviour.

They were immersed, that is, baptized into Christ.

They received forgiveness of their sins.

They received the gift ordinary of the Holy Spirit.

They rejoiced in salvation.

There is no other way for any man to be saved.