And if they had believed in Allah and the Prophet and in (5:81)

Almuntakhab Fi Tafsir Alquran Alkarim

If they were indeed faithful to Allah and to the Prophet Muhammad and gave credence to the Quran sent to him, they would not have sought the infidels’ tutelage, but many of them are indeed wicked

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(5:81) For had they truly believed in Allah and the Messenger and what was sent down to him, they would not have taken unbelievers (instead of believers) for their allies. *103 But many of them have rebelled against Allah altogether.

And if they had believed in Allah and the Prophet and in meaning

*103). It seems natural that those who believe in God and the Prophets and the Scriptures, compared with the polytheists, would naturally be more sympathetic to those who at least share with them belief in God, in prophethood and in .revelation (whatever their disagreements on other religious issues). It was ironic, therefore, that the Jews should openly support the polytheists in the struggle between polytheism and monotheism, and that their sympathies in the conflict between those who rejected prophethood and those who believed in it should lie expressly with the former. Despite all this, they brazenly claimed to be true believers in God, in the Prophets and in the Scriptures.
 

And if they had believed in Allah and the Prophet and in meaning in Urdu

اگر فی الواقع یہ لوگ اللہ اور پیغمبرؐ اور اُس چیز کے ماننے والے ہوتے جو پیغمبر پر نازل ہوئی تھی تو کبھی (اہل ایمان کے مقابلے میں) کافروں کو اپنا رفیق نہ بناتے مگر ان میں سے تو بیشتر لوگ خدا کی اطاعت سے نکل چکے ہیں