Oh, the beauty of the new covenant which is based upon better promises (see Heb.8:6). You see under the old covenant God had a part and man had a part. While God always kept His part; man (i.e. Israel) would consistently fail to keep their part. That is why we see so much judgement from God, in the Old Testament.
Under the New Covenant God took man’s effort out of the equation by sending His Son to become a man and fulfill all the requirements of the law. As if that was not enough; Jesus then takes upon Himself all of the judgement that man’s sin deserved (see Romans 4:25). Under the new covenant God fulfilled both parts of the agreement. Our part; if you will; is to simply believe that He fulfilled both parts of the covenant. Now this is blessed!