The abstract noun "faithfulness" can be stated as "faithful" or "faithfully." Alternate translation: "always faithful to his covenant" or "always faithfully loves his people" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
"he will certainly not clear guilty people." Clearing away people's sin is a metaphor for refusing to punish them. God would not clear away the sin of guilty people. Alternate translation: "He will always punish the guilty" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Punishing people is spoken of as if punishment were an object that could be brought and put on people. Alternate translation: "when he punishes the guilty people's descendants for the guilty people's sins" (See: [[rc://en/ta/man/translate/figs-metaphor]])