The Good News that Muslims will conquer the Known World, and ultimately the Entire World
Allah the Exalted and Most Honored said, while delivering the glad tidings to the believers that the Messenger will triumph over his enemies and the rest of the people of the earth,
﴿ هُوَ ٱلَّذِىٓ أَرۡسَلَ رَسُولَهُ ۥ بِٱلۡهُدَىٰ وَدِينِ ٱلۡحَقِّ ﴾
(He it is Who has sent His Messenger with guidance and the religion of truth,) with beneficial knowledge and righteous good deeds. Indeed, the Islamic Shari`ah has two factors, knowledge and deeds. The true religious knowledge is by definition true, and the accepted Islamic acts are by definition accepted. Therefore, the news and creed that this religion conveys are true and its commandments are just,
﴿ لِيُظۡهِرَهُ ۥ عَلَى ٱلدِّينِ كُلِّهِۦۚ ﴾
(that He may make it superior to all religions.) all the religions of the people of the earth, Arabs and non-Arabs alike, whether having certain ideologies or being atheists or idolaters.
﴿ وَكَفَىٰ بِٱللَّهِ شَهِيدً۬ا ﴾
(And All-Sufficient is Allah as a Witness.) that Muhammad is His Messenger and that He will grant him victory. Allah the Exalted and Most Honored has the best knowledge.
﴿ مُّحَمَّدٌ۬ رَّسُولُ ٱللَّهِۚ وَٱلَّذِينَ مَعَهُ ۥۤ أَشِدَّآءُ عَلَى ٱلۡكُفَّارِ رُحَمَآءُ بَيۡنَہُمۡۖ تَرَٮٰهُمۡ رُكَّعً۬ا سُجَّدً۬ا يَبۡتَغُونَ فَضۡلاً۬ مِّنَ ٱللَّهِ وَرِضۡوَٲنً۬اۖ سِيمَاهُمۡ فِى وُجُوهِهِم مِّنۡ أَثَرِ ٱلسُّجُودِۚ ذَٲلِكَ مَثَلُهُمۡ فِى ٱلتَّوۡرَٮٰةِۚ وَمَثَلُهُمۡ فِى ٱلۡإِنجِيلِ كَزَرۡعٍ أَخۡرَجَ شَطۡـَٔهُ ۥ فَـَٔازَرَهُ ۥ فَٱسۡتَغۡلَظَ فَٱسۡتَوَىٰ عَلَىٰ سُوقِهِۦ يُعۡجِبُ ٱلزُّرَّاعَ لِيَغِيظَ بِہِمُ ٱلۡكُفَّارَۗ وَعَدَ ٱللَّهُ ٱلَّذِينَ ءَامَنُواْ وَعَمِلُواْ ٱلصَّـٰلِحَـٰتِ مِنۡہُم مَّغۡفِرَةً۬ وَأَجۡرًا عَظِيمَۢا ﴾
(29. Muhammad is the Messenger of Allah. And those who are with him are severe against disbelievers, and merciful among themselves. You see them bowing falling down prostrate, seeking reward from Allah and acceptance. The mark of them is on their faces from the traces of prostration. This is their description in the Tawrah. But their description in the Injil is like a seed which sends forth its shoot, then makes it strong, and becomes thick and it stands straight on its stem, delighting the sowers, that He may enrage the disbelievers with them. Allah has promised those among them who believe and do righteous good deeds, forgiveness and a mighty reward.)