Actually,
Frank Herbert aside (I am a BIG fan...) this is an
Islamic term used to describe
conciousness, or
awareness of Allah.
To have Taqwa means to be aware of God's presence as you move through life.
It is an opening experience, and one that creates a spiritual dimension that most people never experience, since it is hard enough being concious of oneself, never mind an all powerful being. Unlike other religions, this sense of presence isn't meant to instil fear, which it would do if you had a naturally guilty conscience. Muslims believe that Allah created all men essentially good, and being watched by Allah throughout one's life gives one a good feeling of being appreciated. You understand that the tiny worries and problems you face everyday are just as important to your character as the big problems that all people fear, and most importantly you realize that you are never alone.
Taqwa has a way of making you strong, it allows you to abstain from temptation and petty crime, since this comes from an attitude that no one knows so no one will care, or at the very least you aren't going to get caught. As a Muslim you realize this is false, after all - He who created you, and sustains you, knows what you are doing, as well as you do. So there is nowhere to hide, and no thoughts to hide either. You must be natural, you must be yourself, if you are angry you must express it, if you are temperate or patient, you must express this as well. You must be human, and your genuine need to improve yourself, and to grow should show itself in your life.
Think of your life as a painting, from birth to death, with each day as a perfect, complete image representing you. God is watching the painting, and the knowledge that he can see the whole picture, and is the painter, is Taqwa. There really isn't any western equivalent for the word, nor is there an equivalent in other religions. When a Muslim challenges an entire army by himself (as happens often in the middle east), and is slaughtered fighting for a good cause, you can be pretty sure that his Taqwa was strong. It lends one the courage to do what is right.
Taqwa eliminates fear, but it also encourages wisdom and prudence. A man who has a family, for him, Taqwa means that he realizes how much he is needed, and how he is shaping the family, and how it is shaping him through every day of his life. Taqwa can make a person strong when facing a constant challenge as well as when faced with a huge deed.
Also, muslims are able to tell Muslims from other people by the Taqwa. A true Muslim is almost always aware of Allah, and this filters through to his or her actions, and the way they speak and carry themselves. It doesn't matter if they are English, Irish, French, Italian, Algerian, Pakistani, Chinese, or any other culture, when a person has Taqwa, it is like they are a lightbulb that is switched on. They sort of glow, you can tell this is a Muslim. At least that is how I see it. Many times people will come and speak to me, and know that I am Islamic, but I don't know who they are and where they are from, but I can tell that they are Muslim, and I am at my ease.
This happens quite a lot in Belfast, where the kind of Taqwa aura separates Irish Muslims from the crowd rather strikingly. They look exactly the same, but I can just tell that they are muslim, and the only difference is the fact that they know that Allah is watching them, and is with them, which is something that I know as well, and other people don't. Maybe that's it. Muslims don't feel alone, Taqwa reminds them that they are all part of the same tapestry, and that while they may not shine to themselves, somewhere out there, someone is watching them sparkle against the backdrop of infinity.