The unmarried encounter various problems - as do the married, but in a different way. I am not so much thinking about moral temptation, though that is only too obvious, but there can be, for instance, loneliness. Many single people live alone, and although many of them may enjoy it, there are many who do not. They can easily miss that vital spark of life that is derived from the interaction of the thoughts and ideas of others.
Such experiences can not only enrich, but can keep one balanced in outlook. Too much loneliness can cause us to go off at a tangent by unmonitored thinking. “Iron sharpeneth iron, so a man sharpeneth the countenance of his friend". (Prov.27:17)
Another difficulty for singles is that they have to live in a society that is largely geared for pairings. They can often feel like the odd one out at social functions, and although their needs regarding holiday accommodation are more sympathetically considered than heretofore, it is still at extra expense. Loneliness also, particularly in the case of females makes them vulnerable to unwelcome approaches.
I have noticed when visiting the North American continent, that in most churches they have a special Ministry to the Singles, including the divorced and the widowed. It gives them a great sense of belonging to a family as indeed the Church is the greatest family in the world, and we should bear in mind the singles when we invite folk to a meal or get-together.