Allah, Blessed and Exalted, is All-Sufficient as a witness on the prophethood of the Prophet, peace and blessings be upon him.

 I take refuge with Allaah from the accursed devil. 
بِسْمِ اللَّهِ الرَّحْمَـنِ الرَّحِيمِ
  Bismillah-ir-Rahman-ir-Raheem: In the name of Allah, the Compassionate, the Merciful. 
  Welcome to my blog and praise the Magnificent Lord as you enter: Allahu Akbar: Allah is the Greatest .
  May the Peace and Blessing of Allah Azza wa Jal, our Lord Glorified and Praised be He, be upon our beloved  Prophet, his Family, and Companions.
Allah, Blessed and Exalted, is All-Sufficient as a witness on the prophethood of the Prophet, peace and blessings be upon him.
لَّـكِنِ اللَّهُ يَشْهَدُ بِمَآ أَنزَلَ إِلَيْكَ أَنزَلَهُ بِعِلْمِهِ وَالْمَلَـئِكَةُ يَشْهَدُونَ وَكَفَى بِاللَّهِ شَهِيداً
(166. But Allah bears witness to that which He has sent down unto you; He has sent it down with His knowledge, and the angels bear witness. And Allah is All-Sufficient as a Witness.)
 إِنَّ الَّذِينَ كَفَرُواْ وَصَدُّواْ عَن سَبِيلِ اللَّهِ قَدْ ضَلُّواْ ضَلَـلاَ بَعِيداً
 (167. Verily, those who disbelieve and prevent (others) from the path of Allah; they have certainly strayed far away.)
إِنَّ الَّذِينَ كَفَرُواْ وَظَلَمُواْ لَمْ يَكُنِ اللَّهُ لِيَغْفِرَ لَهُمْ وَلاَ لِيَهْدِيَهُمْ طَرِيقاً
(168. Verily, those who disbelieve and did wrong; Allah will not forgive them, nor will He guide them to a way.)
إِلاَّ طَرِيقَ جَهَنَّمَ خَـلِدِينَ فِيهَآ أَبَداً وَكَانَ ذَلِكَ عَلَى اللَّهِ يَسِيراً
(169. Except the way of Hell, to dwell therein forever; and this is ever easy for Allah.)
يأَيُّهَا النَّاسُ قَدْ جَآءَكُمُ الرَّسُولُ بِالْحَقِّ مِن رَّبِّكُمْ فَـَامِنُواْ خَيْراً لَّكُمْ وَإِن تَكْفُرُواْ فَإِنَّ للَّهِ مَا فِى السَّمَـوَتِ وَالاٌّرْضِ وَكَانَ اللَّهُ عَلِيماً حَكِيماً
 (170. O mankind! Verily, there has come to you the Messenger with the truth from your Lord. So believe in him, it is better for you. But if you disbelieve, then certainly to Allah belongs all that is in the heavens and the earth. And Allah is Ever All-Knowing, All-Wise.)
Surah 4 An Nisa Verse 166-170
Allah’s statement,
(Verily, We have inspired you…) emphasized the Prophet’s prophethood and refuted the idolators and People of the Scripture who denied him. Allah said,
(But Allah bears witness to that which He has sent down unto you,) meaning, even if they deny, defy and disbelieve in you, O Muhammad, Allah testifies that you are His Messenger to whom He sent down His Book, the Glorious Qur’an that,
(Falsehood cannot come to it from before it or behind it, (it is) sent down by the All-Wise, Worthy of all praise.) Allah then said,
(He has sent it down with His knowledge,) The knowledge of His that He willed His servants to have access to. Knowledge about the clear signs of guidance and truth, what Allah likes and is pleased with, what He dislikes and is displeased with, and knowledge of the Unseen, such as the past and the future. This also includes knowledge about His honorable attributes that no sent Messenger or illustrious angel can even know without Allah’s leave. Similarly, Allah said,
(And they will never compass anything of His knowledge except that which He wills.) and,
(but they will never compass anything of His knowledge.) Allah’s statement,
(and the angels bear witness.) to the truth of what you came with and what was revealed and sent down to you, along with Allah’s testimony to the same,
(And Allah is All-Sufficient as a Witness.) Allah said,
(Verily, those who disbelieve and prevent (others) from the path of Allah, they have certainly strayed far away.) For they are disbelievers themselves and do not follow the truth. They strive hard to prevent people from following and embracing Allah’s path. Therefore, they have defied the truth, deviated, and strayed far away from it. Allah also mentions His judgment against those who disbelieve in His Ayat, Book and Messenger, those who wrong themselves by their disbelief and hindering others from His path, committing sins and violating His prohibitions. Allah states that He will not forgive them;
(nor will He guide them to a way (that is, of good).)
(Except the way of Hell, to dwell therein forever…) and this is the exception. Allah then said,
(O mankind! Verily, there has come to you the Messenger with the truth from your Lord, so believe in him, it is better for you.) This Ayah means, Muhammad has come to you with guidance, the religion of truth and clear proof from Allah. Therefore, believe in what he has brought you and follow him, for this is better for you. Allah then said,
(But if you disbelieve, then certainly to Allah belongs all that is in the heavens and the earth.) Allah is far too rich than to need you or your faith, and no harm could ever affect Him because of your disbelief. Allah said in another Ayah,
(And Musa said: “If you disbelieve, you and all on earth together, then verily, Allah is Rich (Free of all needs), Owner of all praise.”) Allah said here,
(And Allah is Ever All-Knowing,) He knows those who deserve to be guided, and He will guide them. He also knows those who deserve deviation, and He leads them to it,
(All-Wise) in His statements, actions, legislation and all that He decrees.