Genesis page template. Two rows of posts, with each row being a different category. Three posts per row and no pagination.

template-grid-two-categories.php

<?php
/**
 * Template Name: Two Categories in Two Rows
 *
 */

//* Remove the standard loop
remove_action( 'genesis_loop', 'genesis_do_loop' );

//* Add classes to display the posts in a grid
add_filter( 'post_class', 'be_archive_post_class' );

//* The loop for the first category
add_action( 'genesis_loop', 'tj_do_custom_loop_one' );

//* The loop for the second category
add_action( 'genesis_loop', 'tj_do_custom_loop_two' );

/**
 * Breaks the posts into three columns
 *
 * @link http://www.billerickson.net/a-better-and-easier-grid-loop/
 * @param  array $classes An array of post classes.
 * @return array $classes An array of post classes.
 */
function be_archive_post_class( $classes ) {
	global $wp_query;

	$classes[] = 'one-third';
	if( 0 == $wp_query->current_post || 0 == $wp_query->current_post % 3 )
		$classes[] = 'first';
	return $classes;
}

/**
 * First custom loop
 *
 * @param array $args WP Query args
 */
function tj_do_custom_loop_one() {

    $args = array(
	'category_name'  => 'category-3',
        'posts_per_page' => 3,
	'no_found_rows' => true, //* removes pagination
    );

    genesis_custom_loop( $args );

}

/**
 * Second custom loop
 *
 * @param array $args WP Query args
 */
function tj_do_custom_loop_two() {

    $args = array(
	'category_name'  => 'category-2',
        'posts_per_page' => 3,
	'no_found_rows' => true, //* removes pagination
    );

    genesis_custom_loop( $args );

}

//* Runs the framework
genesis();