'Transgressions' in the Bible

Why, then, the law? on account of the transgressions it was added, till the seed might come to which the promise hath been made, having been set in order through messengers in the hand of a mediator --

And because of this, of a new covenant he is mediator, that, death having come, for redemption of the transgressions under the first covenant, those called may receive the promise of the age-during inheritance,