Dear sir
Peace be upon you. ( Al Salam Alykom )
You do not need to declare your Islam before any one. This is a private relationship between you and your Lord, Allah. Islam in dealing with Allah, The Creator is to believe in him alone and to worship Him alone and to uphold the Holy Quran alone. No one has the right to interfere in this relationship between you and Him.
Islam in dealing with people is to be peaceful one, regardless of your religion, sect and/or cult. Every peaceful human is a Muslim , and any one who kills people in the name of Allah is ( Kafer/Moshrik ) , or disbeliever according to his behavior. For more details , please read in our Ahl Al quran site :
http://www.ahl-alquran.com/English/show_article.php?main_id=6306
http://www.ahl-alquran.com/English/show_article.php?main_id=6674
You are very welcome to look at our site to understand Islam and the gap between Islam and Muslims.
Jazaka Allaho Khayran.