All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
The scholars of Fiqh differed in opinion about the first Tashahhud and sitting for it; is it an obligation that invalidates the prayer by deliberately abandoning it, or is it only a recommended Sunnah? There are two views about it; An-Nawawi said:
“The view of the scholars about the ruling on the first Tashahhud and sitting for it: Our view (the Shaafi'i) is that they are Sunnah, and it is also the view of the majority of the scholars, among whom are Maalik, Ath-Thawri, Al-Awzaa'i and Abu Haneefah. Shaykh Abu Haamid and others said: it is the view of most scholars. On the other hand, Al-Layth, Ahmad, Abu Thawr, Is-haaq, and Daawood said: it is a Waajib (obligation). Ahmad said: ‘If someone deliberately leaves out the Tashahhud, then his prayer is invalid, and if he leaves it out of forgetfulness, then he should prostrate for forgetfulness and his prayer is sufficient for him.’”
The view that if someone deliberately leaves it out, his prayer is invalid is the fatwa issued by the Permanent Committee of Iftaa’. The fatwa issued by the Permanent Committee of Iftaa’ reads:
“The first Tashahhud in prayer is one of the obligations of the prayer according to the more correct of the two views of the scholars because the Prophet used to do it, and he said, 'Pray as you saw me pray.’ When he forgot it, he prostrated for forgetfulness (Sujood As-Sahw). If someone deliberately abandons it, his prayer is invalid, and whoever leaves it out of forgetfulness, then he should amend that by prostrating for forgetfulness before he concludes his prayer with Salaam, whether he is an imaam or prays individually.”
According to the view of the scholars who consider the Tashahhud to be obligatory, it is not sufficient for one to only say the Shahaadah (the Two Testimonies of Faith).
Al-Mardaawi, from the Hanbali School of Fiqh, said in his book Al-Insaaf, “The correct view of the School is that the obligation that is sufficient in regard to the first Tashahhud is to say, (At-tahiyyaatu lillahi, salaamun 'alayka ayyuha an-nabiyyo wa-rahmatullah, salaamun 'alayna wa 'ala 'ibaadillahi as-saaliheen. Ash-hadu an laa ilaaha illa Allah, wa anna Muhammadan rasoolullah).”
As you can see, dear Brother, there is a difference of opinion among the scholars regarding the validity of your prayer since you leave the first Tashahhud deliberately. Hence, we first advise you to fear Allah and then to maintain your prayer and perform it in a complete manner that does not subject it to the difference of opinion about its validity, and as the Prophet performed it. The prayer is the most important pillar of religion, and it is only the devil who makes you perform it in a hurry.
Anas, may Allah be pleased with him, narrated that the Prophet said, “Carefulness is from Allah, and hastiness is from the devil.” [Abu Ya'la - Al-Albaani classified it as hasan (good)]
Hastiness in praying in a manner that leads to violating the obligations of the prayer is one of the characteristics of the hypocrites. The Prophet said, “This is how hypocrites pray, this is how hypocrites pray, this is how hypocrites pray: one of them sits (watching the sun), and when it becomes yellow [at the time when it is about to set] and is between the horns of the devil, he stands up and pecks the ground with four (meaning he prays the four units of 'Asr prayer quickly); remembering Allah only seldom during them.” [Ahmad and Abu Daawood]
Allah knows best.