Don't speak in a bellicose manner, but do have the capacity to use violence to achieve your ends, and you will succeed.
The implication is that there is no need to remind others with your words that you can harm them if you actually have the power to do so. They will be reluctant to rile you or to do you harm when they see that you are brandishing a weapon. Applied to a nation, it would be advice to maintain a strong military.
The second could mean something like "Whenever I free a child (from the bondage of child labor) I feel as though I've drawn closer to God." The referent of "it" is not perfectly clear. It could refer to the act of freeing a child, and be saying that the act is a good and charitable act, founded in love, and that it is therefore closer to the way God would have us act towards each other than other kinds of acts.