To find a wife or a husband is to fine a good thing (Pro. 18:22). But prior to finding a wife or a husband, there is usually some urge in the heart to get married.
Natural Urge is that which rises from the fact that one is of age, making one to feel incomplete, unsatisfied, unsettled.
This urge is inherent and latent, but could rise during maturity. The reason for being inherent is the fact that Eve was made from a part taken out of Adam, and when she was brought to him, Adam had a sense of completeness and satisfaction (Gen. 2:21-31). So unmarried men and women could feel incomplete and unsatisfied when they attain maturity.
This urge can arise in the hearts of both believers and sinners alike – bachelors, spinsters, widows, widowers, divorced or separated.