'Observance' in the Bible

As they traveled from town to town, they delivered the decrees decided on by the apostles and elders who were in Jerusalem, for the churches to observe.

Now they have been told about you, that you are teaching all the Jews who are living among the Gentiles to turn away from [the Law of] Moses, advising them not to circumcise their children or to live according to the [Mosaic] customs.

take these men and purify yourself along with them, and pay their expenses [for the temple offerings] so that they may shave their heads. Then everyone will know that there is nothing to the things they have been told about you, but that you yourself also follow and keep the Law.

For we maintain that an individual is justified by faith distinctly apart from works of the Law [the observance of which has nothing to do with justification, that is, being declared free of the guilt of sin and made acceptable to God].

And [you have heard how] I surpassed many of my contemporaries among my countrymen in [my advanced study of the laws of] Judaism, as I was extremely loyal to the traditions of my ancestors.

yet we know that a man is not justified [and placed in right standing with God] by works of the Law, but [only] through faith in [God’s beloved Son,] Christ Jesus. And even we [as Jews] have believed in Christ Jesus, so that we may be justified by faith in Christ and not by works of the Law. By observing the Law no one will ever be justified [declared free of the guilt of sin and its penalty].

For if I [or anyone else should] rebuild [through word or by practice] what I once tore down [the belief that observing the Law is essential for salvation], I prove myself to be a transgressor.

circumcised when I was eight days old, of the nation of Israel, of the tribe of Benjamin, a Hebrew of Hebrews [an exemplary Hebrew]; as to the [observance of the] Law, a Pharisee;