A Successful Savior

What is required for a man to inherit eternal life? Can a man disobey the any of the law even one time in order to be condemned? What is it that the law can do for a sinner? Why do sinners have to be perfect? How is Joshua a type of the LORD Jesus Christ? Did God give the law as a means of salvation? Why couldn't Moses, in representing the law, lead the children of Israel into the Promised Rest? Did the LORD Jesus Christ come into this world to try to save His chosen sinners as some try to preach? Has the LORD failed in anything He has said He would to do?