A non-Muslim friend of mine asked how I could prove the existence of God and why He has given us life, and what its purpose is?
My answer did not satisfy him, please tell me what I should tell him?

I am one of those who send blessings upon the Prophet between 50 and 100 times a day, according to circumstances. I say: “Allahumma salli ‘ala Muhammadin wa aali Muhammad (O Allah, send blessings upon Muhammad and the family of Muhammad).” There are some people who tell me that my sending blessings upon the Messenger of Allah is lacking. Can you tell us – may Allah reward you with good – what is the ideal way to send blessings upon the master of mankind, and is the way I am doing it really lacking?

Is it permissible to pray in a mosque where the ground floor is controlled by the Shi‘ah and the Sunnis control the upper floor?

Can you confirm if Aeisha (radhiallahu 'anha) said this about the Prophet: "His character is the Qur'aan". I have spent hours searching for the daleel but to no avail. Your help will be much appreciated.

What is the Islamic ruling on the issue of imitating the kuffaar in their customs and dealings? What are the guidelines concerning that in Islamic sharee'ah? Is every imitation of the actions of the kuffaar regarded as a haraam kind of imitation, knowing that there are many things that the kaafirs do that are not haraam and are not condemned by sharee'ah, where the one who does them does not do them merely to imitate the kuffaar, but because he thinks those things are good, as Ibn Mas'ood (may Allah be pleased with him) said: "What the Muslims think is good is good before Allah"?  
Please advise us, may Allah honour you, and please give me a detailed answer and explain to me the guidelines on this matter.

Sometimes we hear opinions that were narrated from the Sahaabah, or sometimes other opinions that were narrated from the imams (leading scholars) on various occasions, although the basic principle directs us to follow the Qur'an and Sunnah. When does the Muslim have to follow the opinion of the Sahaabi or imam? How can we reconcile between this and the obligation of following the Qur'an and Sunnah?

Some mobile phones have a Quraan programs which enable one to read the Quraan anytime on the mobile’s screen. Is Taharah (Purity) a condition before one starts reciting?.

Is it permissible to fast without praying?.

I have a question regarding dawah. I am tring to convince my muslim brothers to do dawah to non muslims but hey said that we should fix the muslims first because muslims dont pray etc and so there argument was that is it better to halve a thousand workers in a company and improve them or to get a thousand more, So is dawah fard .

What is sincerity, and what are the benefits of sincerity?

Will a person (a believer) be rewarded if he listens to the Qur’aan without understanding what he is listening to, but he knows that it is Qur’aan? Or will he not be rewarded unless he understands what he is hearing? I hope you could give some evidence from the Qur’aan and saheeh hadeeth.