Continuing the observation that we cannot make it to / please God on our own, Billy Graham has illustrated our dilemma this way:
Suppose for a moment that the requirement for going to heaven is for a person to swim from California to Hawaii. Some people wouldn't make it 500 feet, because they can't swim. Some people won't make it more than a couple of hours / miles because they lack the conditioning and strength. But even the greatest long distance swimmer or an Olympic gold medalist is not going to make it either. At a distance of about 2,400 miles no individual has the ability to make the journey on his or her own. The only way to get to Hawaii is for someone to take you there.