'Religion' in the Bible

but they had some issues with him concerning their own religion, and concerning a certain Jesus, who was dead, whom Paul claimed to be alive.

having known me for a long time, if they are willing to testify, that in accordance with the strictest party of our religion I lived [as] a Pharisee.

which [things] {although they have}, to be sure, an appearance of wisdom in self-made religion and humility and unsparing treatment of the body, {do not have any value} against the indulgence of the flesh.

If anyone thinks he is religious, [although he] does not bridle his tongue but deceives his heart, this person's religion [is] worthless.

Pure and undefiled religion in the sight of our God and Father is this: to look after orphans and widows in their affliction, [and] to keep oneself unstained by the world.