2. Since God possess infinite perfection in all things, the proposition: "Be perfect as your Celestial Father is perfect," if taken literally would presuppose the possibility of attaining absolute perfection. If it were given to Man to be as perfect as his Creator, then he would become his equal, which is inadmissible. But the people to whom Jesus spoke did not understand this nuance, which caused Him to limit Himself to the presentation of a model and tell them that they must strive to reach it.
Those words then must be understood in the sense of relative perfection, that which humanity is capable of achieving and which most nearly approaches the Divinity. What does this perfection consist of? Jesus said: "In loving one's enemies, in doing good to those who hate us, in praying for those who persecute us." In this way He shows that the essence of perfection is charity in its most ample form, because it implies the practice of all the other virtues.
In fact, by observing the results of all the vices and even of simple defects, it can be recognised that there is not one which does not more or less disfigure the sentiment of charity, because all of them have their beginnings in selfishness and pride, which are the negation of it. This is due to the fact that everything which over-stimulates our self-esteem destroys, or at least weakens, the elements of true charity which are: benevolence, indulgence, abnegation and devotion. Love for one's fellow creatures, when extended to love for one's enemies, cannot be allied to any defect which is against charity. Therefore for this reason it is always an indication of a greater or lesser moral superiority. From this it follows that the degree of perfection is in direct relation to the extent of this love. It was for this reason that Jesus, after having given His Disciples the rules of charity and all that they contain of the most sublime, said to them: "Be perfect, as your Celestial Father is perfect."