Sin is...

Sin is...transgression of the law

Deuteronomy27:26 "Cursed be he that confirmeth not all the words of this
law to do them."

If we offend in one point we have offended in all. Sin is real, it offends G-d and He has provided the remedy in the shed blood of Yeshua, His Son

Sin is...

Sin is... knowing to do good and not doing it, it is sin to him
Genesis 4:7 "If thou doest well shalt thou not be accepted? and if thou doest not well, sin lieth at the door."

Another way of saying what sin is..."Therefore to him that knoweth to do good and doeth it not, to him it is sin."

Are you...

Are you a sinner,( a transgressor of G-d"s law, one who has failed to always to do good)
Do you know what to do about your transgressions?