John wrote: 1Jn 3:4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.
... The "law" is the ten commandments. In order to commit sin we must somehow transgress one of the ten commandments.
Is there more to obey than just the ten commandments? Absolutely...
For example - if I refuse to obey the command to love my neighbor as I love myself I would be committing sin because I would be breaking the first commandment. By refusing to love my neighbor as Yahweh commanded then I am making myself "god" before Yahweh.
Exo 20:3 Thou shalt have no other gods before me.
Does the Torah apply to us today? Absolutely - but not all of the Torah..
Paul wrote to Timothy:
2Ti 3:15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
The "holy scriptures" could only be the Old Testament writings which Timothy was taught by his mother and grandmother as a child. (see 2 Tim 1.5) The New Testament did not exist as a book when Timothy was a child.
Paul said that we were to look to the Old Covenant writings for instruction in righteousness...
2Ti 3:16 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: 2Ti 3:17 That the man of God may be perfect, throughly furnished unto all good works.
Again that statement could only apply to the Old Testament writings. BUT it does not apply to all of the Mosaic law system of the Torah. Nobody can keep all of the Torah as there is no Temple.
The ten commandments and all of the moral precepts of the Torah apply to us today. The ceremonial statutes, judgments and ordinances such as the food laws and feasts do not apply to the children of Yahweh under the New Covenant.