Whether suffrages performed by sinners profit the dead?

Objections

Objection 1 : It would seem that suffrages performed by sinners do not profit the dead. For, according to Jn. 9:31, "God doth not hear sinners." Now if their prayers were to profit those for whom they pray, they would be heard by God. Therefore the suffrages performed by them do not profit the dead.
Objection 2 : Further, Gregory says (Pastoral i, 11) that "when an offensive person is sent to intercede, the wrath of the angered party is provoked to harsher measures." Now every sinner is offensive to God. Therefore God is not inclined to mercy by the suffrages of sinners, and consequently their suffrages are of no avail.
Objection 3 : Further, a person's deed would seem to be more fruitful to the doer than to another. But a sinner merits naught for himself by his deeds. Much less, therefore, can he merit for another.
Objection 4 : Further, every meritorious work must be a living work, that is to say, informed by charity. Now works done by sinners are dead. Therefore the dead for whom they are done cannot be assisted thereby.
Objection 5 : On the contrary, No man can know for certain about another man whether the latter be in a state of sin or of grace. If, therefore, only those suffrages were profitable that are done by those who are in a state of grace, a man could not know of whom to ask suffrages for his dead, and consequently many would be deterred from obtaining suffrages.
Objection 6 : Further, according to Augustine (Enchiridion cix), as quoted in the text (Sent. iv, D, 45), the dead are assisted by suffrages according as while living they merited to be assisted after death. Therefore the worth of suffrages is measured according to the disposition of the person for whom they are performed. Therefore it would appear that it differs not whether they be performed by good or by wicked persons.