In John 5:42 Jesus stated:
ἀλλʼ ἔγνωκα ὑμᾶς ὅτι ⸉τὴν ἀγάπην τοῦ θεοῦ οὐκ ἔχετε⸊ ἐν ἑαυτοῖς (John 5:42, NA28)
But I know that you do not have the love of God within you. (John 5:42, ESV)
Why they recited in the Shema:
וְאָ֣הַבְתָּ֔ אֵ֖ת יְהוָ֣ה אֱלֹהֶ֑יךָ בְּכָל־לְבָבְךָ֥ (Deut. 6:5, MT)
You shall love the LORD your God with all your heart (Deut. 6:5, ESV)
What is particularly disturbing is ἐν ἑαυτοῖς (in yourselves) = בְּכָל־לְבָבְךָ֥ (in your heart) except כָל makes it with all your heart. Making this parallel, Jesus isn't denying they had some love for God, but they were more concerned about how they looked to other people rather than loving God with all their hearts, souls, and strength. Jesus challenged human nature's ability to fulfill the Shema.