WE ARE RIGHTEOUS BECAUSE OF CHRIST
Since Christ is in us, the spirit is alive because of righteousness. Christ has given us His righteousness; we're not only declared righteous, we are righteous because we have a new nature, the nature of Christ within - His very life and righteousness! When He died, He took our old sinful self down to the grave with Him, and when He rose He raised us up a new holy, self in Him! We're new creations, with a new self created in righteousness and true holiness (Eph. 4:24). We've been perfected forever (Heb. 10:14). Since we've been justified (made innocent and right with God), there's no condemnation because it's God Himself who says we're right with Him!
We delight in God's law in the inner (real, true) self. We don't want to sin; it's not our nature. We've been given a new heart that desires to do good and longs to please Him, and He has caused us to walk in His ways. He's given us a new heart that won't turn away from Him, and He's promised He won't turn away from us or stop doing good to us (Jer. 32:40). He's taken away our sin and made us good! When joined to sin, we were separate from Him. Now joined to Him, we're separate from sin! So now we can stop worrying about sin and just enjoy our being together with Him!
Having His perfect righteousness, we have a perfect relationship with Him always (righteousness means right relationship). We are right with Him always, even when we sin or fail! We never lose that relationship or go out of fellowship! Christ earned all this for us and gave it to us as a gift.