Leviticus 16:20-22

The blood of the first goat symbolizes the shedding of blood to pay for sins. That is the redemption price that has to be paid. But think about it. Just because there is a payment for sin does not mean that the sins suddenly disappear. The sins are there, they have just been paid for. They have been redeemed, the price for the penalty has been shunted aside because the right price has been paid.

But there is still the sins, they need to be removed. They need to be gotten out of the way. They need to be taken away, and this is where the second goat comes in. The second goat symbolizes those sins being borne away, gotten rid of, removed as far as east is from the west as Psalm 103:12 says.

Both parts, both goats, if you will, are necessary parts of the sacrifice. And because both parts are necessary to the sacrifice, it had to be shown in two goats. One goat could not do it because the one goat is slain. How could that slain goat carry the sins into the wilderness? It is impossible, so it had to be another goat just like it. So like it that lots had to be thrown, if you will, to tell which goat would do which part. It did not matter. That is the reason why they they cast lots. It was just to differentiate which goat would die and which goat would be led away into the wilderness.