The Messenger Muhammed, peace and blessings be upon him, was sent as a warner

 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.
The Messenger Muhammed, peace and blessings be upon him, was sent as a  warner.
يس
(1. Ya Sin.)
 وَالْقُرْءَانِ الْحَكِيمِ
(2. By the Qur’an, full of wisdom,)
 إِنَّكَ لَمِنَ الْمُرْسَلِينَ
 (3. Truly, you are one of the Messengers,)
 عَلَى صِرَطٍ مُّسْتَقِيمٍ
(4. On the straight path.)
تَنزِيلَ الْعَزِيزِ الرَّحِيمِ
 (5. Sent down by the Almighty, the Most Merciful,)
 لِتُنذِرَ قَوْماً مَّآ أُنذِرَ ءَابَآؤُهُمْ فَهُمْ غَـفِلُونَ
(6. In order that you may warn a people whose forefathers were not warned, so they are heedless.)
لَقَدْ حَقَّ الْقَوْلُ عَلَى أَكْثَرِهِمْ فَهُمْ لاَ يُؤمِنُونَ
 (7. Indeed the Word has proved true against most of them, so they will not believe.)
Surah 36 Yasin Verse 1-7
Tafsir Ibn Kathir
By the Qur’an, full of wisdom) means, Al-Muhkam (perfect) which falsehood cannot come to from before it or behind it.
(Truly, you) means, O Muhammad,
(are one of the Messengers, on the straight path.) means, following a straight methodology and religion, and an upright Law.
(Sent down by the Almighty, the Most Merciful.) means, this path which you have brought is a revelation from the Lord of might Who is Most Merciful to His believing servants. This is like the Ayah:
(And verily, you are indeed guiding (mankind) to the straight path. The path of Allah to Whom belongs all that is in the heavens and all that is on the earth. Verily, to Allah all matters return.) (42:52-53).
(In order that you may warn a people whose forefathers were not warned, so they are heedless.) This refers to the Arabs, for no warner had come to them before him. The fact that they alone are mentioned does not mean that others are excluded, just as mentioning some individuals does not mean that all others are excluded. We have already mentioned the Ayat and Mutawatir Hadiths which state that the mission of the Prophet is universal, when we discussed the meaning of the Ayah:
(Say: “O mankind! Verily, I am sent to you all as the Messenger of Allah.”) (7:158).
(Indeed the Word has proved true against most of them,) Ibn Jarir said, “The punishment has become inevitable for most of them, because Allah has decreed in the Mother of the Book (Al-Lawh Al-Mahfuz) that they will not believe.
(so they will not believe. ) in Allah, or in His Messengers.