To be alone in the Bible represents being free of evil and false influences. That's why the Lord seeks solitude to pray, and why the nation of Israel is often described as "dwelling alone." When "alone" is used in reference to ownership – when something is "his and his alone" – the meaning is more literal.

In Genesis 2:18, man being alone signifies that the first men became unwilling to be led by the Lord, desiring to lead themselves. In ancient times people who were "Alone" constituted those led by the Lord as celestial men, and evil spirits no longer infested them. But the Jewish church was not meant to be fully under the Lord's guidance and desired to be among the other nations (away from God); and as one who desires is already in evil, this was granted. (Arcana Coelestia 138, 139)

In Genesis 32:24, being alone or by himself signifies good and truth procured. (Arcana Coelestia 4273)

In Exodus 18:14, being alone signifies a state without influx of truth from good from any other source. (Arcana Coelestia 8689)

In Psalm 102:7, alone by itself signifies something of insignificance, and without relative assocation. The state of being alone here symbolizes a prayer of the Lord when in temptations even to despair. (The Inner Meaning of the Prophets and Psalms 352)

In Psalm 136:4, the Lord alone signifies that only the Lord has formed heaven and the church by means of His Divine Truth. (The Inner Meaning of the Prophets and Psalms 386)

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.