Although the values of the American creed are always espoused in politics, they are usually not brought out and pursued with singleness of purpose. (religion-online.org)
It means singleness of purpose, sincerity and honesty within, as well as avoidance of exterior clutter, of many possessions irrelevant to the chief purpose of life. (nwei.org)
Sincerity is singleness of purpose, particularly as regards the concordance of external form with inner substance. (religion-online.org)