23and I will strike her children dead.And all the churches will know that I am he who searches mind and heart, and I will give to each of you according to your works.
The term you refers to the people of the church in Thyatira (in contrast to all the churches of the previous phrase).
23 and I will strike her children dead. And all the churches will know that I am he who searches mind and heart, and I will give to each of you according to your works.