Eryximachus expresses great satisfaction at Aristophanes' speech and claims that if speakers of any lesser degree than Agathon and Socrates were up next there would be nothing left to say. Socrates remarks that if Eryximachus were in his position, not having spoken yet and having to follow Agathon, he would be quite frightened. Agathon replies that Socrates is trying to fluster him by suggesting that everyone expects a great speech from him. Socrates answers that, having seen Agathon at the festival, he knows that Agathon can speak with great confidence before large crowds. Agathon points out that a small group of intelligent people is far more intimidating than a large crowd. Socrates begins to question Agathon, suggesting that everyone gathered here was in the crowd at the festival, but Phaedrus cuts them off, suggesting that Agathon should make his speech.
Agathon points out that all the previous speeches have spoken only of the benefits that humans have gained from Love, but none of them have discussed the nature of the god himself. Agathon suggests that Love is the happiest of the gods because he is most beautiful and best. He is beautiful because, contrary to Phaedrus' claim, he is the youngest of the gods. He always avoids old age, and only associates with the young. Further, all the horrible things the gods did to each other in ancient times they did because of Necessity and not Love. Since Love has ruled amongst the gods, they have been far more peaceful.
Further, Agathon suggests that Love is sensitive. Rather than settle in the hard parts of humans and gods, on the ground or in the skull, Love settles in our minds and characters. Further, Love will only settle in the minds and characters of those with soft natures, and will move on when he finds someone with a tough character. That he can pass unnoticed in and out of our minds suggests further that the god is fluid.
Agathon goes on to speak about the virtues of Love. Love is just because he is never forced and never uses force: everyone consents to his authority. Love practices moderation, since he can master pleasures and desires. Love is braver even than Ares, god of war, since Ares fell in love with Aphrodite and was thus mastered by Love. Love is wise since he is the inspiration for all other acts of wisdom. No poet can be wise without love, nor could the gods or muses master their respective arts without love for those arts. The gods only became organized when Love came into being, and were motivated by a love of beauty. Before that time, they were governed by necessity and did all sorts of horrible things.
Agathon concludes with a rhetorically complex eulogy praising every aspect of Love, who is responsible for beauty, excellence, mildness, wisdom, goodness, excellence, and much else besides.
Not only in the Symposium, but in other of his writings, Plato is skeptical about the value of tragedy. He suggests that it uses poetic devices and other tricks to produce an emotional response without carefully considering the moral value of these responses. And while Aristophanes' myth represents the comic perspective on love, it is difficult not to read Agathon as giving the tragedian's position on love. What we get from Agathon, however, is not tragedy so much as rhetoric. His speech employs a number of rhetorical devices well known to the ancient Greeks, and the speech as a whole follows the traditional formula for the eulogy. What Plato seems to want us to draw from this speech is that tragedy, like the tragedian, is a superficial and showy genre that does not teach us much, but impresses us into agreement through its fanciful style.
You do not have to look outside you as everything is in your "self", everybody is the two energies (woman-man/yin-yang/...) and if you awaken your "opposite" you are "one", you are realized, totally happy. This is called e.g. in the Bible the Holy or Mystic Marriage. Also the alchemists describe it as "Coniunctio Oppositorum", the Philosopher's Stone, make Gold from Lead,... See the writings of the Mystics too. Etc.