Those who were given the Scripture- the Jews, who used to bring good tidings of the coming of Prophet Muhammad (saws) from the Torah- as Allah (swt) says:
ٰ﴾إِنَّ الدِّينَ عِندَ اللَّهِ الْإِسْلَامُ ۗ وَمَا اخْتَلَفَ الَّذِينَ أُوتُوا الْكِتَابَ إِلَّا مِن بَعْدِ مَا جَاءَهُمُ الْعِلْمُ بَغْيًا بَيْنَهُمْ ۗ وَمَن يَكْفُرْ بِآيَاتِ اللَّهِ فَإِنَّ اللَّهَ سَرِيعُ الْحِسَابِ﴿
(Indeed, the religion in the sight of Allah is Islam. And those who were given the Scripture did not differ except after knowledge had come to them – out of jealous animosity between themselves. And whoever disbelieves in the verses of Allah, then indeed, Allah is swift in [taking] account.) (Ali-Imran: 19)
The division here is the difference, as they were divided after clear knowledge had come to them. Hence, they were
They were divided and differed, and they became suspicious, and the book that had been revealed to them contained the good tiding of the coming of Prophet Muhammad (saw). However, they neither committed themselves to it nor did they believe in our master the Messenger of Allah (saw).
They had been united on the matter of believing the Messenger of Allah (saw), and when he came, they differed and divided. Some of them believed, such as Abdullah bin Salam, who was a Jewish rabbi, and the monk Bahira believed as well. But many others did not believe and they disagreed after the Messenger of Allah (saws) had come to them out of envy from themselves.
﴾وَمَا أُمِرُوا إِلَّا لِيَعْبُدُوا اللَّهَ مُخْلِصِينَ لَهُ الدِّينَ حُنَفَاءَ وَيُقِيمُوا الصَّلَاةَ وَيُؤْتُوا الزَّكَاةَ ۚ وَذَٰلِكَ دِينُ الْقَيِّمَة﴿
(And they were not commanded except to worship Allah, [being] sincere to Him in religion, inclining to truth, and to establish prayer and to give zakah. And that is the correct religion. (5))
Allah (swt) has not commanded in all the previous heavenly books except to worship Him (swt) alone and to be sincere in worshipping Him (swt), this is the message of all the Messengers:
ٰ﴾ وَلَقَدْ بَعَثْنَا فِي كُلِّ أُمَّةٍ رَّسُولًا أَنِ اعْبُدُوا اللَّهَ وَاجْتَنِبُوا الطَّاغُوتَ﴿
(And We certainly sent into every nation a messenger, [saying], “Worship Allah and avoid Taghut.) (An-Nahlf: 36)
Worshipping means the adherence to an allowed action, and avoiding a forbidden action. Allah (swt) says:
﴾ وَمَا خَلَقْتُ الْجِنَّ وَالْإِنسَ إِلَّا لِيَعْبُدُونِ ٰ﴿
(And I did not create the jinn and mankind except to worship Me.) (Adh-dhariat: 56)
Therefore, the purpose of creation is the establishment of the method, and the worship of Allah (swt). It is not only to sit in the mosques and remembering Allah (swt), rather, it is an approach that includes life, values and all ethics.
مُخْلِصِينَ (sincere): Sincerity is the filtration of any of the impurities that afflict the doctrines and corrupt the deeds, it is an action of heart that recognizes the oneness of Allah (swt), and that there is no doer but Allah (swt), there is no creator but Allah (swt), there is no giver of life but Allah (swt), there is no bestower but Allah (swt), there is no preventer but Allah (swt), there is no harmful but Allah (swt), and there is no beneficial but Allah (swt).
One may say that sincerity is in the heart, and as long as the man harms nobody, it is not necessary to pray or perform any other act of worshipping since his intention is right and pure. The answer is: The issue is not only intentions, rather it is deeds and intentions. Allah (swt) says in the Qudsi hadith:
(Sincerity is one of My secrets, and I will place it in the heart of those whom I love of My servants).
Because they have been sincere to Him in religion.
حُنَفَاءَ (inclining to truth) That is, tending and inclining away from polytheism to righteousness. Therefore, Allah (swt) described our master Ibrahin (pbuh) as being (inclining toward truth), meaning that he was tending from worshipping idols. So this word is the measure of the righteousness and commitment to Allah’s orders, so that your deeds are only for the sake of Allah (swt).
They are straight in belief, worshipping and forwarding to Allah(swt), and they are straight, as well, in applying Allah’s orders, whether they are acts of worship, morals, dealings, or legislations.
However, the prayer is the title of everything, and Zakat (obligatory charity) is the title of social solidarity.
Prayer means establishing relation with Allah (swt). Prayer is a declaration of the continuation of the loyalty to Allah (swt). Prayer is the pillar of religion, whoever has established it, has established the religion, and whoever has destroyed it, has destroyed the religion. It is the secret of relatin between the slave and his Lord (swt).
As for zakat (obligatory charity), it is intended for the purification of the soul and the purity of the heart. It reflects a feeling towards others. As if that, prayer and zakat are a relationship with the Creator and with the creatures. This is the heavenly message, hence, they cannot be means of people’s misery, nor can they be extremism and terrorism. This is the correct religion and this is the religion of the just and righteous creed.
وَذَٰلِكَ دِينُ الْقَيِّمَةِ (and that is the correct religion): We note here that the Arabic word of “religion” came masculine, and the Arabic word of “correct” came feminine. “Correct” is a description of the religion or creed, and “religion” combines deeds and sayings; the testimony that there is no god but Allah (swt), and the actions such as prayer, zakat (obligatory charity) and others. However, the action of heart is required with the actions of speech.
 Jami’ Al-Ahadiths Al-Qudsi. Hadith No. 42.