By Truth, love, and growth.
Speaking the truth in love, we are to grow up in every way into Him Who is the head, into Christ.
Ephesians 4:15 (ESV)
These three words summarise the life of a Christian. Christians are those who accept and believe the truth, who have been loved by God and therefore know how to show love, and as a result of the Truth and Love working together, grow in maturity.
With the Bible as your available source of perfect truth (Psalm 19:7-11), and a personal conviction about showing true Christian love (1 Corinthians 13:4-7), you will grow spiritually, emotionally, and personally into being more like Jesus Christ in the way you think about life and the way your respond to life and other people.
Pursue the truth in your Bible; practise the love as you ought, and you will grow.
O, and to put it all in context, Ephesians 4:16 says that the place for this all to work the fastest and most effective, is the body of Christ, the Church. In all your interactions with other Christians, make your part a building-up part.