What does Revelation 1:15 mean?

John describes Jesus further as having feet like burnished brass refined in a furnace. Likely, the reference is to brass that has turned white in the process of burning. The word for "burnished brass" is unique, and seems to only occur in the book of Revelation in all of ancient Greek literature (Revelation 2:18). It appears to be a compound of the Greek words for metals such as brass, and bronze, and the Greek term for frankincense, probably a reference to its whiteness. This makes sense of John's explanation that the appearance was like something glowing in a furnace.

The bronze altar in the temple was used for making sacrifices for sin and for expressing in fire God's judgment on sin. Jesus suffered on the cross to take upon Himself God's judgment for our sin. First Corinthians 15:3 states plainly that Christ died for our sins. He alone is worthy to execute judgment on all sinners that reject Him.

The apostle Paul told the assembly on Mars Hill that God has "fixed a day on which he will judge the world in righteousness by a man whom he has appointed; and of this he has given assurance to all by raising him from the dead" (Acts 17:31). Revelation 20:11–15 describes the final judgment of the wicked of all periods of history. If a person's name is not found in the book of life, he or she is cast into the lake of fire.

John reports that Jesus' voice was like the roar of many waters. Isaiah 42:13 associates a loud voice with that of a warrior shouting aloud as a mighty man against his enemies. So Jesus will show Himself mighty against His foes.