# For certain men have slipped in secretly among you

"For some men have come in among the believers without drawing attention to themselves"

# men who were marked out for condemnation

This can also be put into the active voice. Alternate translation: "men whom God chose to condemn" (See: [[rc://en/ta/man/translate/figs-activepassive]])

# who have changed the grace of our God into sensuality

God's grace is spoken of as if it were a thing that could be changed into something horrible. Alternate translation: "who teach that God's grace permits one to continue to live in sexual sin" (See: [[rc://en/ta/man/translate/figs-metaphor]])

# deny our only Master and Lord, Jesus Christ

Possible meanings are 1) they teach that he is not God or 2) these men do not obey Jesus Christ.