The religion of the earlier Prophets was Islam. How they worship Allaah? I mean praying how did the earlier Prophets pray?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

The religion of all the Prophets is one, which is the religion of Islam. Allaah Says (which means): {Indeed, the religion in the sight of Allaah is Islam.}[Quran 3:19]. Moreover, the Prophet said: "All the Prophets are brothers of different mothers but their religion is one." [Al-Bukhari] As regards how the earlier Prophets worshipped Allaah, then the answer is that they worshipped Him according to the Law that Allaah Has sent down to them in revelation. Every Prophet and his people worshipped Allaah as He ordained them to do. Among the acts of worship that Allaah commanded His previous Prophets and their nations to do is fasting. Allaah Says (which means): {O you who believe! Observing the fasting is prescribed for you as it was prescribed for those before you, that you may become pious.}[Quran 2:183]. They used also to perform the prayers and pay the Zakah. Allaah Says [speaking about Ismaa'eel [Ishmael] (which means): {And he used to enjoin on his family and his people the prayers and the Zakah, and was to his Lord pleasing [i.e. accepted by Him].}[Quran 19:55]. Allaah Says about 'Eesaa [Jesus] (which means): {And He has made me blessed wherever I am and has enjoined upon me prayer and Zakah as long as I remain alive. And [made me] dutiful to my mother.}[Quran 19:31-32]. Allaah further Says about Moosaa [Moses] that he told his people (which means): {We inspired to Moosaa (Moses) and his brother: ''…and make your houses [facing the] Qiblah and establish prayer and give good tidings to the believers."}[Quran 10:87].

The previous Prophets and their nations used also to perform pilgrimage. Allaah Says (which means): {And (remember) when We showed Ibraaheem (Abraham) the site of the (Sacred) House (the Ka'bah at Makkah) (saying): "Do not associate anything with Me and purify My House for those who perform Tawaaf (circumambulation) and those who stand [in prayer] and those who bow and prostrate. And proclaim to the people the hajj [pilgrimage].}[Quran 22:26].

Furthermore, it is confirmed that the Prophet said: "(I perceive) as if I am seeing Moosaa [Moses] coming down from the mountain track, and he is calling upon Allaah loudly (saying: Here I am! In response to your call my Lord!). Then he came to the mountain track of Harsha. He (the Prophet said: "Which is this mountain track?" They replied: "It is the mountain track of Harsha. He observed (I feel) as If I am seeing Yoonus (Jonah), son of Matta on a well-built red dromedary, with a cloak of wool around him and the rein of his dromedary is made of fibers of date-palm, and he is calling upon Allaah (saying: Here I am! In response to your call!)." [Muslim]

As regards whether or not their prayer, fasting and Zakah were like ours, the answer is that only Allaah Knows best how these acts of worship were performed. Knowing exactly how they used to worship does not entail us to act upon it and there is no great benefit in knowing about it; we are ordered to worship Allaah according to the Law which was revealed to the Prophet Muhammad .

Allaah Knows best.