JSFiddle - React, Tailwind, and code Playground

HTML

<div class="testimonials">
<div class="a">hello</div>
<div class="a">wsdf</div>
<div class="a">vishal</div>
</div>

CSS

.a{display:none;}

JavaScript

$('.testimonials div:first').show();

setInterval(function(){ $('.testimonials div:first-child').fadeOut(function(){
   $(this).next('div').fadeIn().end().appendTo('.testimonials')
}) },3000);