Deliberately Praising an Innovator Is Tantamount To Having Loyalty to an Enemy of Allaah
Imaam Fudayl Ibn Iyaad (rahimahullaah) said:
‘Whoever frightens an innovator away, Allah will grant him safety on the Day of Great Terror.’ Shaikh Saaleh Al-Fawzaan commented saying: whoever frightens him by way of speech and (shows) him rejection, then Allah will reward him on the day of judgment- with a good reward on the day of Great Terror because he rejected an evil deed; but if he commends and praises him, this is from hypocrisy and (having) loyalty to the enemies of Allah.
[Surce: It-haaful Qaaree. Vol 2 pages 322-326]