The ESV translates ἀληθεύω as "speaking truth" whereas more literal translations like YLT translates it as "being true". Why is there a difference, especially as it impacts application (being lovingly truthful in speech only versus the whole of one's life)?
15 Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ, 16 from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love. (ESV)
15 and, being true in love, we may increase to Him [in] all things, who is the head -- the Christ; 16 from whom the whole body, being fitly joined together and united, through the supply of every joint, according to the working in the measure of each single part, the increase of the body doth make for the building up of itself in love. (YLT)