House
A "house" is essentially a container -- for a person, a family, several families or even a large group with shared interests (think of the term "houses of worship.") In the Bible, a "house" is also a container, but for spiritual things rather than natural things. In various uses a "house" can represent part of the mind, the whole mind, a whole person or even a church. The other nuance to the word "house" is that it is generally used in regards to our affections and desires rather than our thoughts and principles. This makes sense; we tend to engage our thoughts and rationality when we are out in the world doing our work, but when we are inside our houses we are driven most by love for our families and the desire to be good to those we love. So "house" tends to represent the things we want and care about -- which are ultimately the things that define us.
Arcana Coelestia # 139
139. In ancient times those who were guided as celestial people by the Lord were said 'to dwell alone', for the reason that evil forces, or evil spirits, were infesting them no longer. This was also represented in the Jewish Church by their dwelling alone after the nations had been driven out. For this reason several times in the Word the Lord's Church is described as 'alone', as in Jeremiah,
Rise up, go up against a nation at ease that dwells securely. It has no gates or bars; they dwell alone. Jeremiah 49:31.
In the prophecy of Moses,
Israel dwelt securely, alone. Deuteronomy 33:28.
And plainer still in Balaam's prophecy,
See, a people, it dwells alone, and is not reckoned among the nations. Numbers 23:9.
Here 'nations' stands for evils. These descendants of the Most Ancient Church did not wish to dwell alone; they did not wish to be a celestial man, that is, to be guided as a celestial man by the Lord, but to be among the nations, as also did the Jewish Church. And since this was what they desired it is said, 'It is not good that the man should be alone'. Indeed when this is what a person desires, he is already under the influence of evil, and his wish is granted.
