Acts 1:5 — “For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence.”
The strongest evidence from the New Testament is that Jesus intended water baptism as well as Spirit baptism.
Why?
In Matthew 28:19, Jesus told the disciples to "make disciples... baptizing them." If that referred only to Jesus baptizing people in the Spirit, it would be difficult for the disciples themselves to carry out the command. The wording suggests an action the disciples were to perform.
Also, after Jesus' resurrection and ascension, the apostles consistently baptized converts in water: • About 3,000 people at Pentecost (Acts 2). • The Ethiopian official (Acts 8). • Cornelius and his household (Acts 10). • The jailer at Philippi (Acts 16).
What's especially interesting is Acts 10. Cornelius and those with him received the Holy Spirit first, and then Peter still ordered that they be baptized in water. That suggests the early church viewed Spirit baptism and water baptism as related but not identical.
That said, some Christians emphasize that the essential saving work is Christ's baptism in the Spirit, not the water itself. They would agree with the observation that Jesus is the One who truly changes people, while water baptism is a sign, testimony, or act of obedience.
So the question touches on a real theological debate. But historically, most Christians conclude that Jesus commanded water baptism because the apostles understood His command that way and practiced it throughout the New Testament.