Here "power" probably refers to his authority to judge the world. Here "glory" may refer to a bright light. God sometimes shows his greatness with a very bright light. AT: "powerfully and gloriously" or "and he will be powerful and very glorious"
Sometimes when people are afraid, they crouch down in order to avoid being seen or hurt. When they are no longer afraid, they get up. AT: "stand up with confidence"
Lifting the head is a metonym for looking up. When they lift their heads up, they will be able to see their rescuer coming to them. AT: "look up" (See: [[rc://en/ta/man/translate/figs-metonymy]])
God, who delivers, is spoken of as if he were the deliverance that he causes. AT: "because your deliverer is coming to you" or "because God will soon save you" (See: [[rc://en/ta/man/translate/figs-metonymy]])