The apostle John writes of this change at the start of his Gospel. He says,

And of His fullness we have all received, and grace for grace. For the law was given through Moses, but grace and truth came through Jesus Christ.

John 1:16-17 - NKJV

The coming of Jesus Christ introduces a new economy, a new dispensation! We need to pause for a moment and think about what is meant by a dispensation. There's a good definition of it found on GotQuestions.org. This is the explanation given there, “A dispensation is a way of ordering things - an administration, a system, or a management. In theology, a dispensation is the divine administration of a period of time; each dispensation is a divinely appointed age.”

The new dispensation brought to us by Jesus Christ was to be a divine administration operating on the economy of grace and truth. We call this new dispensation the Dispensation of Grace. This dispensation, that displaced the Dispensation of the Law, is God's divine administration of this age operating on the economy of grace and truth.

Jesus Himself in John's Gospel reveals more about the new dispensation which John started to tell us of in the very first chapter of his Gospel. Jesus says to the Samaritan woman at the well,

“Woman, believe Me, the hour is coming when you will neither on this mountain, nor in Jerusalem, worship the Father.”

John 4:21 - NKJV

The religious requirement of worship at the prescribed place at the designated times is about to pass away! Jesus goes on to tell the Samaritan woman that it is to be replaced by believers worshipping in spirit and in truth. This is a major departure indeed from the religious set up for worshipping the One True God as it had been given to the people of God by Moses. The priesthood of Jesus Christ signals the end of worship in the Jerusalem temple and the end of all associated ordinances and regulations administered by the priesthood that ministered there.

Matthew Henry writes, “The grace that came by the gospel excels all that was before it; the gospel dispensation is more glorious, evident, intelligible, extensive, and effectual, than any dispensation that ever did precede it.“