What does the Bible say about being a true Christian?

According to Revelation 21:7, overcoming is essential for inheriting God's promises, and we see that true Christianity transcends just holding beliefs or attending church. It demands a radical transformation, requiring individuals to confront their own depravity and pride. This is illustrated through the call to crucify the flesh and embrace humility. The faith journey involves constant struggle against temptation and the commitment to uphold holiness in a sinful world, as emphasized in Luke 13:24, where Jesus urges believers to strive to enter through the narrow door.