What you believe concerning Christians is not true. Jews.... walked with Yeshua Messiah and heard and saw in Him - God. They witnessed His life personally. They never forgot what they witnessed. They proclaimed their witness, which was also recorded, and passed it on to all their spiritual descendants in an unbroken line. I am one of their spiritual descendants. I believe their report and equally important, I believe what my heart tells me concerning Jesus. Jesus is Messiah revealed in both OT and NT and in my heart.
In fact they (Christians) spend their entire lifetimes obeying commandments and praying and hoping that they don't go to hell when they die, because they can never be sure.
This is not true. Christians believe that Yeshua and not the Commandments are the way of salvation. Our hope is in the finished work of Yeshua as reparation for sin and reconciliation to Abba. If there are so-called Christians teaching otherwise, they are denying Christ.
I don't think you read what you claim you read. You can start here if you want the real deal.