There is no doubt that Paul knew loneliness, not just by circumstances, but because very few shared his understanding of things revealed by the Spirit, and his deep passion for serving the Lord no matter the cost. In his loneliness, he maintained a confidence we need to emulate: “At my first defense no one came to stand by me, but all deserted me. May it not be charged against them! But the Lord stood by me and strengthened me, so that through me the message might be fully proclaimed and all the Gentiles might hear it. So, I was rescued from the lion’s mouth.” (2 Timothy 4:16–17). Notice that being alone did not deter Paul from “fully” proclaiming the gospel (See Acts 20:24). Those who know their calling from God are not afraid to be alone if necessary.
(1) Man: The Dwelling Place of God, Christian Publications, 1966, page 168.