And Jesus answered him, the first of all the commandments is,

{Hear, O Israel; The Lord our God is one Lord, and you shall worship Him with all your strength and all your might and all your soul and all your heart.}

Mark 12:29

Jesus, peace be upon him, also replied to the devil who was trying to tempt him :

{ Get thee behind me, Satan; for it is written, Thou shall worship the Lord thy God, and Him only shall you serve.}

Matthew 4:10