Be specific. . .how are they deceptive? They truly believe what they are teaching these 'young targets' as you call them, so how is that deceptive?
As I understand...it is not.
They understand differently.
I don’t claim they aren’t sincere in their beliefs. The deception is telling Jews that belief in anything except a supreme, eternal, ephemeral G-d with no physical manifestation whatsoever (which is what belief in the Trinity is) is in line with Judaism. There are others here who could explain it with more acuity than I.
Believing in Jesus completes a Jew. They are still looking for a Messiah, who has already come, and will come a second time.
You don’t get any more Jewish than Saul of Tarsus, who received revelation that Jesus is the Messiah, and “converted” to “Christianity”. He always remained a Jew, and wrote extensively about it in the New Testament for those interested in his experience.
There is NOTHING deceptive about what Jews for Jesus is doing, they are perfectly open and above board about their beliefs and practices.