Add following code in your functions.php file inside your theme folder.
<?php
if(!function_exists('getPageContent'))
{
function getPageContent($pageId,$max_char)
{
if(!is_numeric($pageId))
{
return;
}
global $wpdb;
$nsquery = 'SELECT DISTINCT * FROM ' . $wpdb->posts .
' WHERE ' . $wpdb->posts . '.ID=' . $pageId;
$post_data = $wpdb->get_results($nsquery);
if(!empty($post_data))
{
foreach($post_data as $post)
{
$text_out=nl2br($post->post_content);
$text_out=str_replace(']]>', ']]&gt;', $text_out);
$text_out = strip_tags($text_out);
return substr($text_out,0,$max_char);
}
}
}
}
?>
And to display text you have to call the function like
<?php echo getPageContent(11,150); //First parameter is PAGE ID and second is number of words displayed. ?>