Hadith about Allah's Apostle Revelation

. Their great task is to invite people to worship Allaah and leave offerings Other. [1]
Da'wah to Tawheed and worship only God is the foundation and the way the whole mission of the apostles, as dikhabarkan God in His Word:
ولقد بعثنا في كل أمة رسولا أن اعبدوا الله واجتنبوا الطاغوت
And verily We sent messengers to every people (to call): "Worship Allah (alone), and shun thagut it." (Surat an-Nahl: 36).
In this noble verse, Allah describes the task, the basic mission and the core message of the apostles. That led to monotheism, worship mengikhlaskan only to God and away from all the offerings Other. [2]
This is also mentioned in the Word:
ومآأرسلنا من قبلك من رسول إلانوحي إليه أنه لآ إله إلآ أنا فاعبدون
And We sent not a messenger before thee but We inspired him: that there is no Ilah (the right) but I, so worship Me. (Surat al-Anbiya ': 25).
This is because the apostles were sent to explain the way to the goal of God's creation of man described in the Word:
وماخلقت الجن والإنس إلاليعبدون
And I did not create the jinn and men but that they may worship me. (Surah Az Dzaariyaat: 56).
Tawhid also is the principle of human fithrah ordered to be enforced, as in the Word:
فأقم وجهك للدين حنيفا فطرت الله التي فطر الناس عليها لاتبديل لخلق الله ذلك الدين القيم ولكن أكثر الناس لايعلمون منيبين إليه واتقوه وأقيموا الصلاة ولاتكونوا من المشركين
So with a straight face hadapkanlah to religion (God); (remains of) the nature of God who has created man according to nature's. There is no change in the nature of God. (That's) the right religion but most people do not know, with the return bertaqwalah repent to Him and pray to Him and be steadfast and be not thou of those who ascribe to God. (Surah Ar-Rum: 30, 31).
The apostles asked his people to realize the unity of god in them and with all his ability, they are preaching merealisikan. Suffice story of Noah in Noah's letter as an example of persistence of the apostles in mendakwahkan monotheism to each of his people.
1. Delivering the Shari'ah of God to man and to explain the religion revealed to mankind, as the word of God:
ياأيها الرسول بلغ مآأنزل إليك من ربك وإن لم تفعل فما بلغت رسالته والله يعصمك من الناس إن الله لايهدي القوم الكافرين
O Messenger, deliver what is sent down to you from your Lord. And if not you do (what they're told that means) you do not convey its message. God preserve you from (disorder) humans. Verily Allah does not guide the people who disbelieve. (Surat al Maidah: 67).
بالبينات والزبر وأنزلنآ إليك الذكر لتبين للناس مانزل إليهم ولعلهم يتفكرون
Information (miracle) and the books. And We sent down to the Qur'an, that ye may explain to mankind what has been revealed to them so they think, (Surat an-Nahl: 44).
1. Showing people the good and broke the news to them about the reward prepared for the perpetrators, and warn them of the ugliness and torment prepared for a break. Allah says:
رسلا مبشرين ومنذرين لئلا يكون للناس على الله حجة بعد الرسل وكان الله عزيزا حكيما
(Those We sent) apostles as the bearer of glad tidings and warning in order that no reason for man denies God after the messengers that. And Allah is Mighty, Wise. (Surat an-Nisa ': 165).
1. Improve manusai by example and set a good example in word and deed. Allah says:
أولئك الذين هدى الله فبهداهم اقتده قل لآأسئلكم عليه أجرا إن هو إلا ذكرى للعالمين
They are the ones who have been given instructions by God, so follow their instructions. Say: "I do not ask reward you in delivering (the Qur'an)". But it is nothing but a warning to all people. (Surat al-An'am: 90).
لقد كان لكم في رسول الله أسوة حسنة لمن كان يرجوا الله واليوم الأخر وذكر الله كثيرا
Ye have indeed in (self) He's a good role model for you (that is) for people who hopes (grace) of God and the (arrival) Day of Resurrection, and he was much in God. (Surat al-Ahzab: 21).
1. The apostles had a duty to uphold and implement the Shari'ah of God among His servants. Word of God l:
وأن احكم بينهم بمآأنزل الله ولاتتبع أهواءهم واحذرهم أن يفتنوك عن بعض مآ أنزل الله إليك فإن تولوا فاعلم أنما يريد الله أن يصيبهم ببعض ذنوبهم وإن كثيرا من الناس لفاسقون
and ye judge between them by what Allah hath revealed, and then do not follow their vain desires. And be careful you are against them, so they do not turn you from some of what Allah hath revealed unto you. If they turn away (from the law of God has revealed), then know that Allah wills to afflict them because of the disaster to some of their sins. And in fact most men are rebellious transgressors. (Surat al Maidah: 49).