Jesus came to fulfill the law. And in Matt 5-7 we get a glimpse of what it meant to do so. It is not an adherence to the letter of the law, but to the heart and spirit of God's will for us in daily life. Because we as humans are the way we are (in Paul's words, slaves) we like to know what we MAY NOT do. So seven of the 10 commandments are prohibitions. Jesus makes us realise that "not stealing" is not the equivalent of "be generous." Not being bad is not the same as being good.
His take is that the whole law (and prophets) is summarised in Love the Lord your God with all your heart and with all your mind and with all your strength, and Love your neighbour as yourself. These are such vastly open commands, that they truly set us free FOR something (rather than FROM something). As to the keeping of the sabbath, Jesus "destroyed the temple" as the centre of worship, and sanctified the daily meal of "bread and wine" so that EVERY DAY becomes as holy as the old sabbath. Paul tells us in Romans 12:1 "I appeal to you therefore, brethren, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship." Put this alongside Jesus' own admonition: "If any one will come after me, let him deny himself, take up his cross daily, and follow me!" and for me every day is a holy day. "This is the day that the Lord has made; let us rejoice and be glad in it." (Psalm 118:24)