Create Wordpress Page on Theme Activation

functions.php

// Create a page on theme activation

function privateMessagePage () {

	$default_pages = array('This content is private'); //Page Title
	
	$existing_pages = get_pages();
	$temp = array();

	foreach ($existing_pages as $page) {
		$temp[] = $page->post_title;
	}
	
	$pages_to_create = array_diff($default_pages, $temp);
	
	 foreach ($pages_to_create as $new_page_title) {
		$defaultPage = array(
		  'comment_status' =>'closed',
		  'ping_status' =>'closed',
		  'post_content' => 'This content is restricted to site members. Please contact us for more details.',
		  'post_excerpt' => 'This content is restricted to site members. Please contact us for more details.',
		  'post_name' => 'private-content',
		  'post_status' => 'publish',
		  'post_title' => 'This content is private',
		  'post_type' => 'page'
		);  
		
		$result = wp_insert_post($defaultPage);	
	}
}

add_action('init', 'privateMessagePage');