What does it mean to be a true Christian according to the Bible?

According to Scripture, particularly in Acts 26:18, a true Christian is identified by the opening of their eyes to the truth, turning from darkness to light, and being delivered from the power of Satan. This transformation comes with a heartfelt faith that receives forgiveness of sins. Additionally, true Christians live in adherence to God’s commandments and serve Him with a sincere desire. The Apostle Paul elaborates that true believers are accustomed to manifesting the fruits of their faith, aspiring to cultivate Christ-like character and actively engaging in a life of worship and service. Their lives bear witness to the work of the Holy Spirit, affirming their identity as children of God.