The facts in which a Muslim believes and acts are:
That Allah is one who has no partner. He is Everliving, All-Knowing, All-Powerful, All-Hearing, All-Seeing and Ever-Existing.
That we can't see Allah with our eyes. He has no physical body and is not confined in some place. He never sleeps nor becomes sick or weak. He is perfect and pure of all sorts of defects.
That Allah does not need anyone or anything but everything is needy to Him.
Allah is the creator of the universe who gives it life. He has not created anything without a purpose. Everything in the universe is created with a system and order based on wisdom.
Allah is just. His works are based on justice and righteousness. He is kind to all. He has shown people the right way. He does not make people do bad things nor does He like anything bad for them. The wrongdoers, due to their own choice of doing bad deeds, will face punishment. Allah will give each person his reward or punishment.
A Muslim believes in the truthfulness of all the prophets who had taught the Divine Guidance to mankind. Prophet Muhammad (pbuh) is the last prophet and after him there will be no other prophets. Allah chose him as His messenger to teach the whole of mankind His guidance regardless of any colour, race, or locality.
A Muslim obeys Allah's orders and puts them into practice in all his activities. He believes in the Day of Resurrection, paradise, and hell. On that day people will be brought to life again and will get their rewards with regards to their bad and good deeds.
A Muslim believes in the Imams (Divine Leaders), the prophet's successors, who teach us the guidance of Allah better than anyone else (Peace Be Upon Them All).