It would be easy to prove that suicide is as lawful under the Christian dispensation as it was to the Heathens. There is not a single text of scripture which prohibits it. That great and infallible rule of faith and practice which must controul all philosophy and human reasoning, has left us in this particular to our natural liberty. Resignation to Providence is indeed recommended in scripture; but that implies only submission to ills that are unavoidable, not to such as may be remedied by prudence or courage. Thou shalt not kill, is evidently meant to exclude only the killing of others, over whose life we have no authority. That this precept, like most of the scripture precepts, must be modified by reason and common sense, is plain from the practice of magistrates, who punish criminals capitally, notwithstanding the letter of the law. But were this commandment ever so express against suicide, it would now have no authority, for all the law of Moses is abolished, except so far as it is established by the law of nature. And we have already endeavoured to prove that suicide is not prohibited by that law. In all cases Christians and Heathens are precisely upon the same footing; Cato and Brutus, Arrea and Portia acted herocially; those who now imitate their example ought to receive the same praises from posterity. The power of committing suicide is regarded by Pliny as an advantage which men possess even above the Deity himself.
Deus non sibi potest mortem consciscere si velit quod homini dedit optimum in tantis vitae paenis.
Essays on suicide, and the immortality of the soul: ascribed to the late David Hume, Esq. Never before published. With remarks, intended as an antidote to the poison contained in these performances, by the editor. To which is added, two letters on suicide.' Oxford Text Archive, Oxford University. iBooks.
David Hume - Wikipedia