That which is lawful is right, just and moral.
That which is legal is permitted by the State (conformity to the rules within a fictional jurisdiction) applied to men and women who have abandoned their freedom in return for protection (citizenship).
As is clear to see, that which is lawful is not necessarily legal. To judge what is right by whether it is legal is to work on blind faith that the State is run by honourable people. If you require a framework of legislation (pertaining to legal) to conclude right from wrong, you lack a basic grasp of morality. And someone who lacks morality can not be expected to do that which is right, e.g., Lawful.
To engage in that which is Lawful is to exercise your free will in a manner that violates no other. To engage in that which is legal without a thought to what is moral, is to entrust the unscrupulous, the self serving, the psychotic and the duplicitous (politicians) to dictate your actions, forgoing your own discernment.
To reference legislation as the source of validation in support of an action is a fallacy when government can create out of thin air any dictate it desires to fit a preexisting agenda, devoid of moral, just or righteous attributes. Obedience to the dictates of politicians does not guarantee rightful action, it does however guarantee a level of servitude.
Lawful and legal therefore are the antithesis of each other.