Her husband is forcing her to wear niqaab and she wants advice
Question

I wear Hijab but do not wear Niqab, my husband says that if I do not start covering my face then he will divorce me. He says that whatever he asks me to do I should do. I do not want to disobey my husband but to wear niqab would cause me great hardship and sadden me deeply. I guess it is due to lack of eeman that I feel this way but feel that he is trying to force me to do something that I do not want to do. Can you please advise me on this matter.
Praise be to Allah.The evidence of the Qur’aan and Sunnah indicates that it is obligatory for women for cover their faces. This evidence includes the verse in which Allaah says (interpretation of the meaning): 
“O Prophet! Tell your wives and your daughters and the women of the believers to draw their cloaks (veils) all over their bodies (i.e. screen themselves completely except the eyes or one eye to see the way)”
[al-Ahzaab 33:59] 
The cloak (jilbaab) is a garment that the woman places over her head and lowers over her face. 
So you have to fear Allaah in this matter and respond to two commands: the command of Allaah and the command of your husband. Undoubtedly this will be very good for you. This matter will make your husband happy and bring happiness to your home. Feelings of difficulty will pass if you are patient and get used to it. These feelings of difficulty will turn to joy when you see the effect that your way of dressing has on him, so you will be responding to Islamic commands and the command of your husband which is in accordance with the laws of Allaah. You will be closing the door to the shaytaans of those who may look at you, and will also be protecting the gaze of chaste and good people from looking at something which they are not permitted to see. And there are other benefits which you will see and appreciate when you respond to this command. 
Sisters who wear niqaab often come to regret the years in which they used to uncover their faces, after Allaah honoured them with the niqaab. If one of them were to be given all the wealth in the world to uncover her face, she would not do it. We have even seen many chaste women who have left their husbands because they wanted them to take off the niqaab. So think about the great difference between your situation and theirs. Where now can we find a man who is keen to keep his family chaste and covered? There are very few of them. Should we disregard these few or should we appreciate their actions which spread good in society? 
We remind you to fear Allaah, and we remind you of the actions of the believing women when they responded to the command of Allaah (interpretation of the meaning): 
“and to draw their veils all over Juyoobihinna (i.e. their bodies, faces, necks and bosoms)”
[al-Noor 24:31]
al-Bukhaari (4481) narrated that ‘Aa’ishah (may Allaah be pleased with her) said: “When this verse was revealed, the muhaajir women took their waist wrappers and tore them at the edges, and covered their faces with them. 
See also the answer to question no. 21134, which explains the obligation of women covering their faces. 
Your husband should also read question no. 20343, which explains the husband’s duty to offer sincere advice to his wife, and ways of doing that. 
And Allaah knows best.