What is the importance of being truthful, both in personal and business relationships, in Islam? Is lying ever considered and (acceptable) action?

What are the signs of Allah's love for His slave?

A very common problem seen in youth in western countries is that their parents allow them to indulge in some form of haram in the hope that will stop them from committing worse haram. An example of this is that parents will say that they allow their children to indulge in music in the hope that will stop them from going out with bad people or leaving their home all together. Parents are afraid that if they enforce the law of Allah in their homes, that their children will leave. 

What is Islam's position on this sort of compromise? Some parents also say that they only have the duty to tell their children something is haram, and then their children have to choose for themselves because they are already young adults (i.e. 13 -18 years old and unmarried, living at home). Don't the parents have to forbid haram by all means, or do they just say that is haram and then leave them be? To what extent do parents have to go to forbid their children from haram?

Parents also believe that once their children reach the age of puberty they are no longer responsible for their sins or actions, and so say they will have no sin if they advise their children something is haram and then leave them. Is this true? Or do parents always have the responsibility of forbidding their children from haram, and will they be responsible if they see their children doing haram and just leave them after advising them?

What are the things that a Muslim woman may uncover in front of a kaafir woman, such as a Buddhist woman for example? Is it true that she is not allowed to uncover her face?

If the Muslims celebrate the birthday of the Prophet (blessings and peace of Allah be upon him), why do they not celebrate the birthday of the Prophet of Allah ‘Eesa (peace be upon him)? Is he not a Prophet who was sent from Allah, may He be glorified and exalted? I heard this idea from someone, and I know that Christmas and the celebration thereof is haraam, but I want an answer to this question. May Allah reward you with good.

I don't celebrate Christmas in any way, but my 11 year old daughter loves the beauty of a Christmas tree when decorated. Is it permissible for me to have one in my house throughout the year?

In my school it is Christmas time. My school has this Christmas tradition. Every year a classroom gets an adopted family that is poor so they can buy gifts, food, and donate money to them for Christmas. Unfortunately, I have refused to donate any money or give any food for the following reason: These denotations will be done in the name of Christmas, so that when the adopted family receives these donations, they will say "God Bless The Christians". 
Am I right for refusing to give donations?

How is major ablution done? There are differences of opinion in a number of madhhabs, so who should I follow?
How did the Messenger (blessings and peace of Allaah be upon him) to minor and major ablution?.

I am usually out at school most of the day and I have to use the bathroom, I can't just go home to make Istinjah. Should I make Wudu and pray or should I miss the prayer and make it up later?.

What should a husband do if he discovers on the wedding night that his wife is not a virgin because she did not bleed?

Is it necessary for someone to seek refuge from Satan before reading every chapter of the Qur’ân if he is reading more than one chapter in one sitting?

Why does Islam prohibit adoption? Adoption is a good thing. It provides a home, a set of parents, and a loving family to children who otherwise would grow up without such blessings. Why does Islam prohibit children who have no one from belonging to a family?