Commenting on Luke 16:28, Gerhard notes that those in hell do not love but are concerned only to lessen their torments. There is no evangelism in hell. His concern for his five brothers is not evangelistic but selfish:
They will be tortured by the punishments of their kin. Thus the rich man wants to forewarn his brothers not out of love and a desire for their safety but out of fear and terror that the sight of the punishments prepared for them will increase his own torments.
On Death, § 303 (9).