Mercy is not getting what we do deserve. What do we deserve? Hell! But, if we believe in Christ and accept the free gift of salvation, we do not have to spend eternity in hell. Instead, we will get to spend eternity in heaven with Jesus. There will be no suffering, no tears in heaven. But in hell there will be continual torment for the unsaved.
Why do we deserve hell? Because we do not live up to God's standards. We lie, we cheat, we steal. We covet, we lust after things of this world, and we take the Lord's name in vain. None of us can say we have never sinned. Yes, some of us are "better" than others. But, none of us are good without the blood of Christ covering us.
Are you saved? Have you accepted the free gift? If not, you should really think about it!