Tie breaker?

That would be the most disappointing thing that could happen.

But if we do beat Atlanta next week in this scenario, it keeps Atlanta from resting it's players.

Atlanta won't be able to rest its players the last week regardless. Because if we beat Baltimore and Atlanta, and Atlanta beats Seattle but loses to us, we'd both be 12-3 going into the last week. Atlanta would have to beat Carolina to clinch the division, because we could still win it with a win over Tampa and an Atlanta loss to Carolina.