James 3:7-12

For every kind of beast and bird, of reptile and sea creature, can be tamed and has been tamed by mankind, but no human being can tame the tongue. It is a restless evil, full of deadly poison. With it we bless our Lord and Father, and with it we curse people who are made in the likeness of God. From the same mouth come blessing and cursing. My brothers, these things ought not to be so. Does a spring pour forth from the same opening both fresh and salt water? Can a fig tree, my brothers, bear olives, or a grapevine produce figs? Neither can a salt pond yield fresh water.

Here we see the previous verse illustrated. In other words this is the evidence of how evil the tongue can be when it is unaffected by God’s grace. The point that these verse make is simply that the tongue is uncontrollable. The tongue is wild, even wilder than the animals that we have dominion over. In verses 9-12 we see the manifestation of this uncontrollable nature of the tongue. We cannot tame the tongue and use it for its highest purpose; which is to glorify God with our speech. Rather, as James points out, we use the same tongue to glorify God and blaspheme Him. This is what we all do with our tongues every day. As I read what James has to say here in these verses I cannot help but think about how ridiculous it is that we cannot control what comes out of our own mouths. God created us in His own image and gave us dominion over His creation, yet because of sin we are unable to control our own tongues. At the though of this we should, to use the words of Ezekiel in Ezekiel 36:32, be ashamed and confounded by our ways.

The first thing that James notes is that all types of creatures are being and have been tamed by the human race. When we read this we should not think that James is saying that all creatures have been tamed and turned into pets. We, from our experience, know that a poodle has not been tamed in the same way that a tiger has. The domestication of every animal on earth is not what James is talking about. If we go back in our Bibles to Genesis 1:29 I think that we will see just what James is talking about.

And to every beast of the earth and to every bird of the heavens and to
everything that creeps on the earth, everything that has the breath of life, I
have given every green plant for food." And it was so.

There in Genesis we find a list that is very similar to James’ list; and we see that God has given human beings dominion over His creation. This is what James is talking about here in James 3.
James also does something very interesting in verse 7 when he describes the dominion that man has over animals. He says that the animals are tamed and have been tamed. By choosing to write it in such a way James is emphasizing that not only are people subduing animals, but this is the natural order (state) of how things work.

What is so ironic, and proves the evil nature of the tongue, is that despite the dominion that humans have over creation we can’t even control our own tongues. Because of sin we can control a gigantic elephant, but we cannot control the small tongue. It was in the fall that man lost dominion over the tongue.
Some English translations do not pick up exactly on what James is saying here, but literally he says that no one among men can tame the tongue. It is not so much that the tongue is so powerful that it is intrinsically impossible to tame it. The reality is that we, by our sinful nature, are so weak that we cannot control our tongues. In Ephesians 4:29 we see what the proper, controlled us of the tongue is. If we look back to Ephesians 4:23 we see that the source of this self-control is not self, but the Spirit. Through the Spirit our words can be edifying. Otherwise our words will be a restless evil full of deadly poison.
The word here that is translated as restless in this verse is translated as double-minded in 1:8. In verses 9-12 we see exactly why James would characterize the tongue as restless or double-minded. Some who is unable to control their tongue (with the help of the Spirit) is inconsistent and untrustworthy. On top of this, James says that their speech is full of deadly poison. Literally James says that the poison of the tongue, or evil words, is death-bearing. Whereas we saw in verse 6 that the source of the evil from the tongue was hell; here we see that its result is death. Our evil words carry death into our lives. In Romans 3:13 we see a similar reference to the speech of people. Later in that same chapter (vv. 23ff) we see that the only anti-venom for the poison of our tongues is Christ.