Who's trying to make you change your mind? It's the Word of God - not a matter of private conscience. 

As the then Cardinal Ratznger said:

"If a Catholic were to be at odds with the Holy Father on the application of capital punishment … he would not for that reason be considered unworthy to present himself to receive Holy Communion. While the Church exhorts civil authorities… to exercise discretion and mercy in imposing punishment on criminals, it may still be permissible to…have recourse to capital punishment. There may be a legitimate diversity of opinion even among Catholics about… applying the death penalty."

However, it contradicts Scripture and Catholic teaching to assert it is always and everywhere wrong regardless of circumstances. And Pope Francis appears to have done so.