Constant feeding of abundant misinformation about Islam, for long period of time, has made it incumbent upon us to provide correct knowledge of what Islam is. Remove misconception and apprehension about Islam, introduce them to beauty-serenity-harmony of excellent teachings prescribed by Islam, they will be indebted to us forever. If we fail to inform them about Islam they will testify against us on the Day of Judgment.
Following verses from Quran directs us in clear words about our duty to inform everyone around us about Islam
Let there from you arise a group of people inviting to all that is good (Islam), enjoining Al Maruf (ie Islamic Monotheism and all that Islam orders one to do) and forbidding Al Munkar (polytheism and disbelief and all that Islam has forbidden). And it is they who are successful. 3.104
You (true believers in Islamic Monotheism, and real followers of Prophet Muhammad and his Sunnah) are the best of peoples ever raised up for mankind; you enjoin Al-maruf and (ie Islamic Monotheism and all that Islam has ordained) and forbid Al-Munkar (polytheism, disbelief and all that Islam has forbidden) and you believe in Allah: 3.110
Thus you are appointed as the model community so that you become witnesses against humankind….”2.143
The same directive is emphasized in the farewell sermon by our beloved prophet (PBUH).
Those who are present should covey (my message) to those who are not.Convey for me even if it is one ayah(Bukhari and others).
Again Quran directs us to follow the footsteps of our beloved prophet (PBUH).
Indeed, in the Messenger of Allah (Muahammed PBUH) you have a good example to follow, for him who hopes for (the Meeting with) Allah and the Last Day, and remembers Allah Much. 33.21
But introducing Islam to Non-Muslims requires lot efforts and resources; every one of us does not possess those skills, tools and resources. So it is prudent to do join our efforts and work together. Al-Furqaan Foundation has published English Translation of the message of The Quran. Al Furqaan also has translation in many other languages. Al Furqaan is trying to make the translation available in all major languages of the world. Over and above this, we have big collection of books about introducing and learning the Islam suitable for every level. We also have resources to train someone for Dawah. Getting connected with Al Furqaan Foundation will give you a exposure to many other organizations and individual who are active in educating others about Islam, which can equip us to be more effective.