Romans 1:31

Verse 31. Without understanding] ασυνετους, from α, negative, and συνετος, knowing; persons incapable of comprehending what was spoken; destitute of capacity for spiritual things.

Covenant - breakers] ασυνθετους, from α, negative, and συντιθημυι, to make an agreement; persons who could be bound by no oath, because, properly speaking, they had no God to witness or avenge their misconduct. As every covenant, or agreement, is made as in the presence of God, so he that opposes the being and doctrine of God is incapable of being bound by any covenant; he can give no pledge for his conduct.

Without natural affection] αστοργους; without that attachment which nature teaches the young of all animals to have to their mothers, and the mothers to have for their young. The heathens, in general, have made no scruple to expose the children they did not think proper to bring up, and to despatch their parents when they were grown old or past labour.

Implacable] ασπονδους, from α, negative; and σπονδη, A LIBATION. It was customary among all nations to pour out wine as a libation to their gods, when making a treaty. This was done to appease the angry gods, and reconcile them to the contracting parties. The word here shows a deadly enmity; the highest pitch of an unforgiving spirit; in a word, persons who would not make reconciliation either to God or man.

Unmerciful] ανελεημονας; those who were incapable, through the deep-rooted wickedness of their own nature, of showing mercy to an enemy when brought under their power, or doing any thing for the necessitous, from the principle of benevolence or commiseration.