Revelation 1:9

I, John, who am also your brother and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the island called Patmos, for the sake of the word of God, and for the testimony of Jesus Christ.

Revelation 6:9

And when he opened the fifth sea, I saw, under the altar, the souls of those who were slaughtered on account of the word of God, and the testimony which they held.

Revelation 11:7

And when they shall have finished their testimony, the savage beast which ascends out of the abyss, shall make war against them, and shall conquer them, and kill them.

Treasury of Scripture Knowledge

Summary

And ye shall be brought before governors and kings for my sake, for a testimony against them and the Gentiles.

Bible References

For a

Revelation 1:9
I, John, who am also your brother and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the island called Patmos, for the sake of the word of God, and for the testimony of Jesus Christ.
Revelation 6:9
And when he opened the fifth sea, I saw, under the altar, the souls of those who were slaughtered on account of the word of God, and the testimony which they held.
Revelation 11:7
And when they shall have finished their testimony, the savage beast which ascends out of the abyss, shall make war against them, and shall conquer them, and kill them.