'Act' in the Bible

For it was fitting for God [that is, an act worthy of His divine nature] that He, for whose sake are all things, and through whom are all things, in bringing many sons to glory, should make the author and founder of their salvation perfect through suffering [bringing to maturity the human experience necessary for Him to be perfectly equipped for His office as High Priest].

For every high priest chosen from among men is appointed [to act] on behalf of men in things relating to God, so that he may offer both gifts and sacrifices for sins.