Our Gemara and Mishna on Amud Aleph tells that the two goats, the one for the scape and the one for the inner sacrifice should be the same size, the same appearance and bought at the same time for the same price. 

What can we find in this symbolism? Peri Tzaddik (Shushan Purim 2) offers an insightful explanation. The two goats, on the outside are indistinguishable, yet on the inside one of them represents absolute and abject sin, while the other one represents the epitome of holiness, entering into the Holy of Holies. This is no accident. It reminds us that God alone can see the difference between two people. The lottery that chooses one goat over the other, despite their apparent similarities, drives this message home. By removing the Cohen’s intent and choice of the goat from the picture and leaving it to seemingly random choice, it allows for the hand of God to make the determination. This shows that only God knows who is truly righteous and who appears to be righteous on the outside, but actually is evil.

The ritual of the two goats serves a wakeup call to all the rationalizations we bring to our prayers on Yom Kippur. We must know that God knows the potential for evil or good that lurks inside, despite outward appearances.