Revelation 2:23 KJV
And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works.
Revelation 2:21–25 KJV Chapter Context
21
And I gave her space to repent of her fornication; and she repented not.
22
Behold, I will cast her into a bed, and them that commit adultery with her into great tribulation, except they repent of their deeds.
23
And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works.
24
But unto you I say, and unto the rest in Thyatira, as many as have not this doctrine, and which have not known the depths of Satan, as they speak; I will put upon you none other burden.
25
But that which ye have already hold fast till I come.