God has given everyone a praise. The question is, do you really receive it and then sing it?
If you are down and depressed, then I would say the answer to that question is no. This verse says that the song has been put our mouths, so we all have what we need to praise. At this point, then, it is up to us to use what God has given us.
So what does come out of your mouth?
If Jesus wouldn't say it, then it is probably not a phrase from the God's new song. And this is not just about fighting words and swearing. It is about every single word that comes out of your mouth - and it can even be extended to the way you think as well. Most importantly, it is about the way you talk to yourself.
Self-talk can make or break your day, your week, your month and, well, you get the picture. In fact, the way you think and talk affects your entire lives. What you say (and think) is what you get.
The song God put in your mouth is a song of praise and wonder. The words are God-like and awesome, reflecting his very own magnificence. Sing God's words back to him - even when it doesn't feel good. Before long, those words will manifest magnificently before your very eyes.