The blood of Christ purifies our conscience from dead works so that we may serve the living God. It does not say: so that we work harder. But: so that we are freed from what paralyzes us inside.
Dead works are actions born from a guilty conscience or religious duty. The New Covenant frees you from this. Not so you become inactive, but so your actions come from freedom instead of fear.
Your conscience is purified. This is not a hope, it is a fact in the New Covenant. From this comes service that is alive and not exhausting.