How does the church grow into maturity? Paul gives his answer in Ephesians 4. It grows by truth and love. To allow ourselves to be hurled hither and thither by the fierce blasts of false teaching is to condemn ourselves and the church to perpetual immaturity (verse 14). Instead, what we need is 'the truth', provided we speak it 'in love' (verse 15). For it is 'in love' that the church grows and builds itself up (verse 16). What Paul calls for is a balanced combination of the two. 'Speaking the truth in love' is not the best rendering of his expression, for the Greek verb makes no reference to our speech. Literally, it means, ‘truthing (aletheuontes) in love', and includes the notions of ‘maintaining', ‘living' and ‘doing' the truth.
Thank God there are those in the contemporary church who are determined at all costs to defend and uphold God's revealed truth. But sometimes they are conspicuously lacking in love. When they think they smell heresy, their nose begins to twitch, their muscles ripple, and the light of battle enters their eye. They seem to enjoy nothing more than a fight. Others make the opposite mistake. They are determined at all costs to maintain and exhibit brotherly love, but in order to do so are prepared even to sacrifice the central truths of revelation.
Both these tendencies are unbalanced and unbiblical. Truth becomes hard if it is not softened by love; love becomes soft if is not strengthened by truth. The apostle calls us to hold the two together, which should not be difficult for Spirit-filled believers, since the Holy Spirit is himself ‘the Spirit of truth', and his firstfruit is ‘love'. There is no other route than this to a fully mature Christian unity.
From God’s New Society (The Message of Ephesians)
By R.W. Stott, InterVarsity Press (Pages 171-172)