Which virtue did only Jesus teach and practice? Almost all religions teach good morals and virtues to their followers. In the case of Christianity the Lord Jesus Christ is not only the center of Christianity, but also the highest perfect model that Christians should follow.
Jesus taught and practiced many virtues that we read in the New Testament, some of which can be seen in some form in other religions that preexist Christianity. However, there are some teachings that Jesus taught and practiced which do not seem to be present in any ancient religions. Therefore, my question: Is there any virtue or teaching based on the New Testament that is unique to Jesus till today?
Through the Sermon on the Mount and the Parables, Jesus taught people to practice the same virtues that they already knew about, but with differences.

What - The same virtues, but to a greater extent. Go the extra mile. (Matthew 5:41)
Who - Show love not only to friends, but to enemies. (Matthew 5:43-48)
When - Pray without ceasing. Recall the neighbor who came at night for bread (Luke 11:5-8) and the Ten virgins, only some of whom were prepared. (Matthew 25:1-13)
Where - Both locally and to the Ends of the Earth. The Great Commission.
Why - Motive to glorify God, not self. Give in secret, pray in a closet. (Matthew 6:1-8)
How - Not by human effort, but by God's power through His indwelling spirit. (John 15:1-17)

From the reaction of the disciples, this widening and deepening of virtue appeared hardest to acccept concerning two of them: forgiveness and generosity.
Forgiveness
17 Jesus said to his disciples: “Things that cause people to stumble are bound to come, but woe to anyone through whom they come. 2 It would be better for them to be thrown into the sea with a millstone tied around their neck than to cause one of these little ones to stumble. 3 So watch yourselves.

“If your brother or sister sins against you, rebuke them; and if they repent, forgive them. 4 Even if they sin against you seven times in a day and seven times come back to you saying ‘I repent,’ you must forgive them.”

5 The apostles said to the Lord, “Increase our faith!”

6 He replied, “If you have faith as small as a mustard seed, you can say to this mulberry tree, ‘Be uprooted and planted in the sea,’ and it will obey you. (Luke 17:1-6)

Generosity
18 A certain ruler asked him, “Good teacher, what must I do to inherit eternal life?”

19 “Why do you call me good?” Jesus answered. “No one is good—except God alone. 20 You know the commandments: ‘You shall not commit adultery, you shall not murder, you shall not steal, you shall not give false testimony, honor your father and mother.’”

21 “All these I have kept since I was a boy,” he said.

22 When Jesus heard this, he said to him, “You still lack one thing. Sell everything you have and give to the poor, and you will have treasure in heaven. Then come, follow me.”

23 When he heard this, he became very sad, because he was very wealthy. 24 Jesus looked at him and said, “How hard it is for the rich to enter the kingdom of God! 25 Indeed, it is easier for a camel to go through the eye of a needle than for someone who is rich to enter the kingdom of God.”

26 Those who heard this asked, “Who then can be saved?”

27 Jesus replied, “What is impossible with man is possible with God.” (Luke 18:18-27)

Perfection
Be perfect, therefore, as your heavenly Father is perfect. (Matthew 5:48)
Jesus' insistence that no one will enter Heaven unless they are morally perfect was his most significant statement.