Many people, who claim that we are under the law of Moses today will claim that without the law then there is no sin. They will claim that sin is the transgression of the law ,using 1 John 3-4, as evidence for the claim.

But this is NOT what this means at all. Sin is NOT the transgression of the law of Moses and it’s pretty simple to explain.

1 John 3-4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.

But sin was in the world BEFORE the law…

(For until the law sin was in the world: but sin is not imputed when there is no law.

If we look at the Greek 
1 John 3-4 Πᾶς ὁ ποιῶν τὴν ἁμαρτίαν καὶ τὴν ἀνομίαν ποιεῖ καὶ ἡ ἁμαρτία ἐστὶν ἡ ἀνομία

The word LAw here is ἀνομία, anomia This means disobedience. It does not mean the law given by Moses.

Sin is the transgression of Gods word…his command…it is simply disobedience to God it does NOT mean to not keep the law.

Adm disobeyed God…he didnt transgress the law of Moses he simply disobeyed God and this was classed as sin.

This is NOT the same word as used for LAW as per Romans 5-13 which is νόμος nomos which is the actual law.

Without the LAW ( nomos) then Sin the disobedience (anomia) to God is not imputed.