Password protecting template, secured content not showing if even password is right

Here is mine below code.
Now thing is that It perfectly asks the password for secured page.

But if even I add correct password. I still page asking for password.

Below is mine code.

<?php
/**
 * Template Name: Page
 *
 */
global $post; 
if ( ! post_password_required( $post ) ) {
get_header();

?>
<div id="Content">
    <div class="content_wrapper clearfix">
secured content here

</div>
</div>
<?php 

get_footer(); 
}else{
    // we will show password form here
    echo get_the_password_form();
}

I solved issue with suggestion of @TheDeadMedic.

Below is the code. As he told added while have post. I added it after header.

<?php
/**
 * Template Name: Page
 *
 */
global $post; 
if ( ! post_password_required( $post ) ) {
get_header();
while ( have_posts() ) { the_post(); }
?>
<div id="Content">
    <div class="content_wrapper clearfix">
secured content here

</div>
</div>
<?php 

get_footer(); 
}else{
    // we will show password form here
    echo get_the_password_form();
}