How do we know that the Spirit of God dwells in us?

According to Romans 8:9, a clear indicator that the Spirit of God dwells in an individual is the presence of a transformed life that walks according to the Spirit. If a person has faith in Christ and exhibits a lifestyle that aligns with the Spirit's leading, it affirms that they belong to Him. This transformation is initiated by being born again, which is the work of the Holy Spirit, signifying that we have become a new creation, empowered to live a life that pleases God. Conversely, those who do not have the Spirit of God are classified as not belonging to Christ.