Showing kindness is an important character in humans that Christianity and Islam encourages. Because of that, it was mentioned in the scriptures as follows


“May the LORD now show you kindness and faithfulness, and I too will show you the same favor because you have done this. 2nd Samuel 2:6
Be kind to one another, tender-hearted, forgiving each other, just as God in Christ also has forgiven you. Ephesians 4:32
The natives showed us extraordinary kindness; for because of the rain that had set in and because of the cold, they kindled a fire and received us all. Acts 28:2
Do not let kindness and truth leave you; Bind them around your neck, Write them on the tablet of your heart. Proverbs 3:3
He has told you, O man, what is good; And what does the LORD require of you But to do justice, to love kindness, And to walk humbly with your God? Micah 6:8


Islam greatly encourages kindness to others. The Prophet Muhammad (SAW) taught kindness and compassion to his people and he was seen to be the ultimate symbol of kindness. His kindness was acknowledged in the Qur’an when it says;

O Messenger of Allah! It is a great Mercy of God that you are gentle and kind towards them; for, had you been harsh and hard-hearted, they would all have broken away from you” [Quran 3:159].
The prophet also talked about the kindness of Allah in a reported hadith that says;
“Indeed, God is kind, and loves kindness. He grants with Kindness what He does not grant with harshness” [Saheeh Muslim] (hadith)