Stapleton's fourth proposition: freedom from deadly sins
Thesis XLIII. In chapter 5 he teaches that in this life the fulfilment of the commandments is not such as to be entirely free of all sin, but that it is such, and so great, that it can and must be entirely free of grave and deadly sins.
The righteous themselves, he grants, sometimes sin mortally. But while they are in such a sin they are not righteous and do not fulfil the law, and true righteousness cannot coexist with such a sin until repentance has blotted it out. The true righteousness of this life does coexist, however, with other, lighter sins, even those committed every day.
Latin
XLIII. Cap. 5. Docet mandatorum impletionem in hac vita talem non esse ut omni prorsus peccato careat: tamen talem & tantam esse ut gravibus illis & lethiferis peccatis omnino carere possit & debeat. Justos quidem ipsos etiam interdum lethaliter peccare: Verum in tali peccato constitutos justos non esse, neque legem implere: nec veram justitiam cum tali peccato, nondum per poenitentiam deleto, consistere, licet cum aliis levioribus peccatis, etiam quotidie commissis, vera hujus vitae justitia consistat.