How do we know we are in Christ Jesus?

Paul asserts in Romans 8 that our assurance of being in Christ is fundamentally linked to the presence of the Spirit within us. If the Spirit of Christ dwells in us, it indicates that we are indeed children of God. This indwelling Spirit cultivates a mindset that shifts our focus from our own righteousness to the righteousness of Christ alone. The Spirit not only assures us of our relationship with God but also empowers us to live in accordance with His will, leading us to seek His glory rather than trust in our fleshly efforts.