In this passage Paul is showing that the individual believer is a person in whom God the Holy Spirit dwells. This is one truth that proves that at our new birth all things become new (2 Cor. 5:17). Our bodies are the temple of God (2 Cor. 6:16). Just as God dwelt by His Holy Spirit in the temple in the Old Testament, so now He dwells in us. Very important when you consider that Paul is talking about Jews and Gentiles being unified together in Christ at salvation.