romans 12:8 Or he that exhorteth, on exhortation: he that giveth, let him do it with simplicity; he that ruleth, with diligence; he that sheweth mercy, with cheerfulness. - Free Bible Online

      8. Or he that exhorteth--Since all preaching, whether by apostles, prophets, or teachers, was followed up by exhortation (Ac 11:23; 14:22; 15:32, &c.), many think that no specific class is here in view. But if liberty was given to others to exercise themselves occasionally in exhorting the brethren, generally, or small parties of the less instructed, the reference may be to them.
      he that giveth--in the exercise of private benevolence probably, rather than in the discharge of diaconal duty.
      with simplicity--so the word probably means. But as simplicity seems enjoined in the next clause but one of this same verse, perhaps the meaning here is, "with liberality," as the same word is rendered in 2Co 8:2; 9:11.
      he that ruleth--whether in the Church or his own household. See 1Ti 3:4, 5, where the same word is applied to both.
      with diligence--with earnest purpose.
      he that showeth mercy, with cheerfulness--not only without grudging either trouble or pecuniary relief, but feeling it to be "more blessed to give than to receive," and to help than be helped.

JFB.