John Wesley on Revelation 12:11

And they have overcome him - Carried the cause against him. By the blood of the Lamb - Which cleanses the soul from all sin, and so leaves no room for accusing. And by the word of their testimony - The word of God, which they believed and testified, even unto death. So, for instance, died Olam, king of Sweden, in the year 900, whom his own subjects would have compelled to idolatry; and, upon his refusal, slew as a sacrifice to the idol which he would not worship. So did multitudes of Bohemian Christians, in the year 916, when queen Drahomire raised a severe persecution, wherein many "loved not their lives unto the death."