James 3:2-3

For we all stumble and sin in many ways. If anyone does not stumble in what he says [never saying the wrong thing], he is a perfect man [fully developed in character, without serious flaws], able to bridle his whole body and rein in his entire nature [taming his human faults and weaknesses]. Now if we put bits into the horses’ mouths to make them obey us, we guide their whole body as well.