'Act' in the Bible

Act now! For the Lord has said to David, 'By the hand of my servant David I will save my people Israel from the Philistines and from all their enemies.'"

When you hear the sound of marching in the tops of the trees, act decisively. For at that moment the Lord is going before you to strike down the army of the Philistines."

So Joab sent to Tekoa and brought from there a wise woman. He told her, "Pretend to be in mourning and put on garments for mourning. Don't anoint yourself with oil. Instead, act like a woman who has been mourning for the dead for some time.