Should I bless my enemies?

Romans 12:14Bless those who persecute you. Don’t curse them; pray that God will bless them.

Our natural inclination is to get revenge on our enemies, but Jesus instructs us to bless them and seek God’s blessing on them (see Matthew 5:43-48). Praying for your enemies is a severe test of your devotion to Christ. Which is the greater blessing: to win over your enemies to God’s cause or to continue fighting with them?