The Shema Israel (“Hear 0’ Israel”) is read in weekly Jewish synagogue services and is composed of Deuteronomy 6:4-9 and 11:13-21, and Numbers 15:37-41. The most famous portion is Deuteronomy 6:4-9:
4 “Hear, O Israel: The Lord our God is one Lord; 5 and you shall love the Lord your God with all your heart, and with all your soul, and with all your might. 6 And these words which I command you this day shall be upon your heart; 7 and 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. 8 And you shall bind them as a sign upon your hand, and they shall be as frontlets between your eyes. 9 And you shall write them on the doorposts of your house and on your gates.
Catholics wholeheartedly affirm Deuteronomy 6:4-5, because what these verses teach is timeless. However, beginning in verse 6, we see affirmed aspects of Old Covenant law which are no longer binding in the New Covenant, as Jesus came to fulfill that law and, in doing so, perfected it (Matt. 5:17-18). These would include liturgical and dietary laws that do not obligate Christians in the New Covenant who, for example, celebrate the Mass as the fulfillment of the Passover (1 Cor. 11:23-32; see 1 Cor. 5:7) and no longer observe changeable disciplines that held that certain animals were unclean and thus could not be consumed (see Acts 10:9-16).
Consequently, Catholics cannot affirm the Shema unconditionally in its original, complete form.