Jesus in the Gospel of Saint Matthew teaches us about the ethical love: Love your enemies, Matthew 5:44. Jesus in this passage of the Gospel of Matthew speaks to us of the love of charity, of the love projected towards the whole creation of God (love of the spirit). This form of love is also called Agape, or love without passion (Thomas Aquinas).
Although Jesus taught in the Aramaic language, the first Gospels were written in the Greek language. In the ancient Greek language there was no designation for the word love, remember that love is a gender. In the Greek language each form of love was designated by its own name, example: Agape (love of the spirit), Philia (love of the soul), Eros (love of lovers).
The love of Charity constitutes, together with faith and hope, one of the three theological virtues according to Thomas Aquinas, that is to say, Charity is an infused virtue, a charism, a grace. These virtues perfect and complete the cardinal virtues that are justice, prudence, temperance and fortitude.
This expression of Jesus, in Matthew 5:44, about love is equivalent to the expression "do not hate your enemies". It is in essence the unconditional love, the love that forgives and reconciles, the love that expands by itself to the neighbor and the whole creation of God. The Charity lacks fear, this is so because fear supposes guilt or punishment (1 John 4:18), and therefore charity also lacks of hate and wrath.
An example of this form of love is the parable of the prodigal son, of that unconditional love of the father who forgives the son who sinned.
This is the love of the "full of the holy spirit," of the "enlightened," of the "wisdom doctors." This form of love (Agape) is extremely important because it enables men to understand and acquire knowledge about the "key of science" (Luke 11:52), the science of God, the wisdom.