We also have a law that states that a child under a certain age cannot be charged with criminal offences. In any society good laws need to be based upon an individual's responsibilities, to themselves, and to the greater society. Rights cannot exist in a moral vacuum. Liberty without boundaries is not liberty, its slavery. Slavery to a system that robs us all.
Biblical morality is based upon the concept of covenant.
Covenant means and obligation, treaty or pact and a relationship between two parties. A relationship is established, not necessarily an equal one, but a legal one. It is biding, and it's law. Some even claimed that legal marriage was the antithesis of love, and turned a man-woman relationship into nothing more than legalised prostitution. From the Biblical perspective love can only exist where there is law.