Christianity is trapped in a self-deprecating myth called “total depravity”, a contortion on the concept of the current diminished state of humanity. They believe that they are wicked beyond repair, principally by no fault of their own but through naturally falling into the fallen state that persists since Adam. The only way out is accepting vicarious atonement. Any attempt to pull yourself out of the mire by your own strength is misguided and counterproductive, as it leads to more guilt and shame. Baron Münchhausen is the patron of this conviction, who finds himself in the middle of a swamp, and is only able to rescue himself by grabbing his own braid of hair, and with his own strong arm, pull himself out, and his horse as well, clutched between his knees.
That’s about as preposterous as Christians will consider the concept of “getting righteous” or “getting right with G-d” through their own means. Many, if not most Christians are trying to be good people. They want to be righteous, and also do good works, however, their ploy is to trick themselves out of their total depravity by deliberately not performing any good deeds in order to become righteous, but only out of gratefulness for a salvation that has freely been given to them. Even if it’s psychologically damaging, you can only humbly accept the “free gift of grace” and then work out your (existing) salvation with fear and trembling, but full of thanksgiving and as directed by the Holy Spirit. Any attempt to do good works as part of repentance or to become a better person are considered legalism.
Christians are not merely trying to be saved through believing correct information (“faith alone”). I think they are trying to outsmart a false premise, which works reasonably well (the premise, not the outsmarting) within a system of guilt and failure. There is a big dollop of arrogance folded into the mix too, as in “oh you poor Jews/Muslims/Buddhists/Hinduists still trying to pull yourself out of the mire by your own hair, have you not realized how futile it is? Join us and receive the free gift of salvation, give up your struggle and then be transformed and become a good person (sanctification) through the force of the Holy Spirit indwelling you!” – to this mindset, preaching Torah-observance is a clear step back into legalism and self-righteousness. It is warm and cosy in this mindset of “I don’t have to do anything” and letting yourself drift in whichever direction the Spirit leads.
However. Torah is not just some set of time-bound laws. It is the principle by which the Universe lives and breathes. More and more Christians are waking up to this. And then there’s nothing wrong with following Yeshua, letting Him guide you to Torah, which He never rescinded – quite the opposite. Christians believe in a process called “sanctification”, by which they improve their moral standing and character, but more as a by-product of loving G-d and Jesus. They want to be a force for good in the world, but the main focus still must be evangelization, “saving souls”. Charity too often is just thinly veiled evangelisation, not worth any reward in itself. Christianity is indeed an exclusive system of “salvation” – through Christ alone. Righteousness will not “save” an individual, at least not own righteousness, but only the “vicarious”, i.e. borrowed righteousness of Jesus. Any other perception means you’re back in the trap of self-righteousness. Oh wretched me! Where do we go from here?