Phineas' Spear

As I read the book of Numbers, I see a toughness in serving God that we don't often see praised. When the Israelites were revolting (again) against God, and one of them publicly flaunted his immorality with an evil woman, a young priest named Phineas thrust a javelin through both their bodies, and in this way stopped the plague. God highly praised Phineas (Numbers 25:6-13). Could I have done it? 

God has not given believers of this current era the power of the sword, so Phineas' decision is not one we need to make. But doesn't following Christ sometimes mean taking a tough stand, or applying a stern measure?