How do we know we are truly Christians?

The presence of the Holy Spirit in a believer's life serves as a definitive assurance of one's status as a Christian. This is articulated in Romans 8:9, where it is revealed that those who do not have the Spirit of Christ do not belong to Him. The evidence of possessing the Holy Spirit is not merely subjective feelings but manifests in a transformed life marked by sanctification. Believers who are indeed Christ’s will display fruits of the Spirit, including a proclivity towards righteousness and a departure from sin, affirming their union with Christ that is both secure and eternal. Such assurance encourages believers to live in light of their new identity and to embody Christ-like characteristics in their daily lives.