It is the same God,
Our God is the one who gave every one his full rights.
One of these simple rights is to believe in him or no.
Regarding MissX question,
In the begining of Islam the non believers wanted to burry Islam, and the non believers started the fight, and Muslims had to defend them selfs.
Muslims never started any fight.
I will answer the questions shortly.
Also remember that the human knowledge is limited.
Why?
Because researchers say that we only use around 21 % of our brain, now may be new studies came and say the usage is more.