What does Ephesians 4:15 mean?

Another sign of maturity in a Christian is the ability to speak the truth in love. Interestingly, the ability to promote what is right with the right attitude is directly contrasted ("rather") to being immature and deceived. Immature believers can fall prey to the false choice of speaking truth without love, or speaking love without truth. The first problem promotes legalism; the second problem promotes depravity. God's command is to grow in maturity, a progression which includes both action and information (Ephesians 4:11–12).

To speak the truth in love includes how Christians communicate with believers and unbelievers alike. Believers are called to live in harmony with one another as family. With unbelievers, we are told to be ready at all times to "make a defense to anyone who asks you for a reason for the hope that is in you; yet do it with gentleness and respect" (1 Peter 3:15). There is no reason why a Christian has to be mean-spirited in order to be accurate when sharing our faith with others. Instead, we should speak the truth in love, letting God's Spirit work boldly in us and through us to help others come to faith in Christ.