All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all, we should say that we are very impressed with regard to your ambition to spread Islam at your age in a society where evil and deviation from the right path is widespread. We ask Allaah to enable you to perform more acts of righteousness and guide you even more to the right path.
It should be noted that calling non-Muslims to Islam is a very important matter. Any person who wants to carry out this task has to do his best and be patient. Indeed, it is required from him to know the misconceptions of the enemies of Islam on religion, and be able to respond to these misconceptions, and be aware of the deficiencies of other religions that are contradicting Islam; one should be wise in doing so. Calling non-Muslims without [religious] knowledge subjects one to being tempted or at least subjected to failure.
A correct and sincere idea may lose its credibility and strength because of the weakness of the religious knowledge of the caller to Islam, or because of the weakness in the method of presenting such ideas. Therefore, we advise the brother to read the books that respond to the misconceptions about Islam, and we advise you to listen to the debates of Ahmed Didat with the Christians. For more benefit you could listen to Ahmed Didat who is specialized in calling non-Muslims to Islam.
As regards the best ways of calling non-Muslims to Islam, we will summarize them in the following:
1) Offer each one of them a translated copy of the meaning of the Quran as a gift, or to make some translated copies available for them to borrow and read at home. According to the statement of some people who propagate Islam, this is one of the best and influential methods of calling to Islam.
2) Invite some callers to Islam to your club for a lecture or presentation. It is better if this is done on a regular basis, like once a week.
3) Invite some new Muslims and ask them the reason which led them to embrace Islam, and ask them how they were before Islam and how they are and feel after embracing Islam. Indeed, this has a very important impact on non-Muslims.
4) Focus on the greatest values in Islam which are lacking in western societies, like being kind and dutiful to the parents, truthfulness, trust, chastity, being kind to neighbours, to the wife and to children and other values which show to non-Muslims the greatness of this religion and that it is truly from Allaah.
5) Focus, if necessary, on the contradictions and discrepancies that exist in their belief and religion, while being wise and having good manners in presenting the arguments and criticisms, and try to address reason as they consider reason as something holy. One has to clarify to them that sound mind and reason do not accept these contradictions and discrepancies.
Allaah knows best.