Spiritually speaking Is our Social Security number the mark of the beast, and our Government, the Antichrist?

No. Further, I do not believe in the teachings of the "Left Behind" series. However, it may be closer to the truth than we realize. The way I understand the "Mark", it must be accepted willingly with full knowledge that in doing so, you are rejecting the teachings of Jesus. In such a situation, I would rather die than reject Jesus.