'Observe' in the Bible

Do you not say, ‘It is still four months until the harvest comes?’ Look, I say to you, raise your eyes and look at the fields and see, they are white for harvest.

Then some of the Pharisees said, “This Man [Jesus] is not from God, because He does not keep the Sabbath.” But others said, “How can a man who is a sinner (a non-observant Jew) do such signs and miracles?” So there was a difference of opinion among them.

If anyone hears My words and does not keep them, I do not judge him; for I did not come to judge and condemn the world [that is, to initiate the final judgment of the world], but to save the world.

One who does not [really] love Me does not keep My words. And the word (teaching) which you hear is not Mine, but is the Father’s who sent Me.