Sermon on the Mount
Jesus was sitting on a mountain and his close disciples were gathered around him. Then the crowds too sat down to listen to him.
He taught them many practical things that can help them improve their day to day living and strengthen their relationship with God.
Foremost amongst these was what they needed to do to be happy. Nine things were mentioned. They needed to be conscious of their spiritual needs, to be peaceable, meek, pure in heart. endure under persecution for his namesake etc.
He further taught them how to pray which became the popular LORD'S PRAYER. He taught them how to settle differences amicably and promptly as well as how to maintain marital chastity. He also taught them how and why they shouldn't be anxious about their daily necessities of life like food, clothing and shelter. He gave practical examples from local things around them showing God cares.
At the end the crowd was astounded at his teaching. See the Bible for more details: Matthew chapters 5 to 7