There are many, many mentions in the Psalms of 'the wicked', and 'mine enemy'. It is easy to think the psalmist is speaking of actual people, other races, other tribes at war with Israel. Maybe he is, but there's certainly other ways of understanding these verses. The wicked here could be well-intentioned acquaintances, those that like giving advice without understanding the problem, or perhaps those who deliberately mislead for their own ends. We've all probably experienced acquaintances like that. The wicked could also be our inner demons, gnawing away at our integrity, leading us astray. If the foundations be destroyed, what can the righteous do? We must stay on guard against poor advice, and against our own temptations, our desire to take the easy route, rather than doing the next right thing. If we let up to much or too often the foundations of our spirit will weaken and there'll be nothing to hold us together.