What does it mean that those in Christ are sealed by the Spirit?
Being sealed by the Spirit means that when a person is in Christ, the Holy Spirit indwells them. This sealing is the Spirit's presence within, confirming the believer's union with Christ. It involves a mutual indwelling: the believer is in Christ, and Christ is in the believer, as seen in Ephesians.
Les teaches that being sealed by the Spirit means the Holy Spirit is in us when we are in Christ. He explains that being in Christ is the secret, and as seen in Ephesians, one who is in Christ has been sealed by the Spirit. Les emphasizes the mutual indwelling: we are in Him and He is in us, which he calls mind boggling. He also connects this sealing to the Christ of the cross, resurrection power, and seated at the Father's right hand, rather than the earthly ministry of Jesus to Israel.