'Alone' in the Bible

He has made everything beautiful and appropriate in its time. He has also planted eternity [a sense of divine purpose] in the human heart [a mysterious longing which nothing under the sun can satisfy, except God]—yet man cannot find out (comprehend, grasp) what God has done (His overall plan) from the beginning to the end.

There was a certain man—without a dependent, having neither a child nor a brother, yet there was no end to all his labor. Indeed, his eyes were not satisfied with riches and he never asked, “For whom do I labor and deprive myself of pleasure?” This too is vanity (a wisp of smoke, self-conceit); yes, it is a painful effort and an unhappy task.

for if either of them falls, the one will lift up his companion. But woe to him who is alone when he falls and does not have another to lift him up.

Again, if two lie down together, then they keep warm; but how can one be warm alone?

And though one can overpower him who is alone, two can resist him. A cord of three strands is not quickly broken.