In Surat al-Hadid, verse 27, God said:
{وَجَعَلْنَا فِي قُلُوبِ الَّذِينَ اتَّبَعُوهُ رَأْفَةً وَرَحْمَةً وَرَهْبَانِيَّةً ابْتَدَعُوهَا مَا كَتَبْنَاهَا عَلَيْهِمْ إِلَّا ابْتِغَاءَ رِضْوَانِ اللَّهِ }
This Verse contains the proof that there are good innovations due to that God praised the believing Muslims among the nation of Prophet ^Isa ( Jesus) who correctly followed him in the matters of the belief and in clearing God from resembling the creation, for the"Rahbaniyyah"( الرهبانية) they innovated.
God praised those followers of Prophet ^Isa because they were people of sympathy and mercy, and for innovating the practice of Rahbaniyyah, which is giving up the worldly matters to an extent that they would not marry because they desired to dedicate their lives entirely for worshipping God, and not to occupy their time in providing the obligatory spending on the spouse and family members. Their living quarters were modest structures built of clay in secluded areas, and there, they dedicated all their time for worshipping God.
In this Verse, God established that He did not obligate Prophet ^Isa's followers with the Rahbaniyyah, and He praised them for innovating this practice which was not ordained upon them in the Injil or in the sayings of Prophet ^Isa. Rather, this was something they innovated and chose to do to exaggerate in obedience to God and be accepted by Him.
This is an example of a good innovation, a proof from the kor'an that a good innovation is permissible and rewardable.