No, He was not lying when He said that,
......nor was He lying when He said the rest of the passage...in verse:
16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
Mark 16:16 The requirements for those who are being saved cannot be undone by the requirements for those not being saved! He who believes and is baptized is still required for salvation? Heaven and earth may pass away but my words shall not pass away!
It is Reasonable that if they reject faith why bother mentioning the second requirement?
1 Corinthians 12:13
For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.
Eph 1:13 4:30 sealed
God says baptism! Ez 36:25:27
Jesus Christ says baptism! Mk 16:16
Peter says baptism! Acts 3:38 1 Pet 3:21
Paul say baptism! 1 cor 1:16 1 cor 12:13
The apostles say baptism! Acts 2:38 acts 8:35