JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
    <div class="change">
        <h1>Box 1</h1>
        <p>Lorem ipsum</p>
    </div>
</div>
<div class="box">
    <div class="change">
        <h1>Box 2</h1>
        <p>Lorem ipsum</p>
    </div>
</div>
<div class="box">
    <div class="change">
        <h1>Box 3</h1>
        <p>Lorem ipsum</p>
    </div>
</div>
<div class="box">
    <div class="change">
        <h1>Box 4</h1>
        <p>Lorem ipsum</p>
    </div>
</div>

CSS

.box {width:45%; background:Red;float:left;margin:10px;}

JavaScript

var testimonialsArray = [
    "<div class='change'><h1>Box 5</h1><p>Lorem ipsum 5</p></div>", 
    "<div class='change'><h1>Box 6</h1><p>Lorem ipsum 6</p></div>", 
    "<div class='change'><h1>Box 7</h1><p>Lorem ipsum 7</p></div>", 
    "<div class='change'><h1>Box 8</h1><p>Lorem ipsum 8</p></div>", 
    "<div class='change'><h1>Box 9</h1><p>Lorem ipsum 9</p></div>" 
];



var order = Math.floor((Math.random()* $('.change').length ));

$('.box').eq(order).find('.change').fadeOut(function(){
   $(this).html(testimonialsArray[Math.floor((Math.random()* testimonialsArray.length))]).fadeIn();
});

//testimonials[3]