“Hear, O Israel: The Lord our God, the Lord is one. You shall love the Lord your God with all your heart and with all your soul and with all your might. And these words that I command you today shall be on your heart. You shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise . . . Deut. 6:4 The shema is a declaration of the belief in one God. However, it is said as a prayer, often with profound concentration and devotion, especially in the morning and evening services.
Jesus said this was the most important commandment in Mark 12:28,29 . . . And one of the scribes came up and heard them disputing with one another, and seeing that he answered them well, asked him, “Which commandment is the most important of all?”Jesus answered, “The most important is, ‘Hear, O Israel: The Lord our God, the Lord is one. And you shall love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.’
Jesus was Jewish so he would have been making this declaration of belief and praying the shema ("Hear, O Israel: the LORD our God, the LORD is One") morning and night along with every devout Jewish person.