Try this one, it work for my ebook
<body>
<div style="text-align: center;"><img alt="knowing God" src="../Images/knowing%20God.jpg" /></div>
</body>
Dont use <p> for cover image
<body>
<p style="text-align: center;"><img alt="knowing God" src="../Images/knowing%20God.jpg" /></p>
</body>