Galatians 2:16

"—know that a man is not justified by observing the law, but by faith in Jesus Christ.  So we, too, have put our faith in Christ Jesus that we may be justified by faith in Christ and not by observing the law, because by observing the law no one will be justified." (NIV)
"—yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified." (ESV)

The two translations put this verse in a slightly different light, but the final message is the same.  The NIV essentially says, "We who have grown up with the law know that it is impossible to uphold the law perfectly, so we put our faith in Jesus because He came as a substitute for the law—because we are incapable of keeping the law, and in turn reaching heaven, Jesus fulfilled the law and became the law, so that whoever puts his faith in Christ has become blameless in God's sight."  The implied message is that, since the Jews know that it is impossible to keep the law, they should not force the Gentiles to learn for themselves before they can receive Christ.  The Jews should teach the Gentiles so that they don't make the same mistakes.  Because Jesus took the place of the law, the Gentiles should be able to go directly to the new Law.

The ESV gives the same message, but with a different undertone: "We Jews grew up with the law, striving to keep it to the best of our ability.  Despite our best efforts, we found ourselves unable to uphold the law, yet we continued to work to obey God.  When Jesus came to save us, rather than being prideful and refusing to believe that all our efforts were worthless, we joyfully and thankfully accepted the justification God offered us in Christ.  Since we so joyfully received Him despite our lives of fruitless efforts, we should not now scorn the Gentiles and make them endure a lifetime of insignificance, but should eagerly accept them into faith in Christ and encourage them to enter into a life of significance immediately so as not to experience the same dread and suffering we did."