One who lives considering these cautiously, resolutely & enthusiastically,
may either enter the state of Nibbāna  right here & now in this very life,
or if there is remaining traces of clinging, the state of non-return...
Those who neglect understanding Misery, Cause of Misery, End of Misery,
and how Misery is completely & irreversibly eliminated, are incapable of
release by understanding, are incapable of mental release, are incapable
of direct knowledge, and are thereby incapable of making an end...
While those who undertake real understanding of Misery, Cause of Misery,
End of Misery, & Way to End Misery, are indeed capable of mental release
by understanding, direct knowledge, and thus capable of making an end...

                    

Dig further here on the 4 Great and Noble Truths:
http://What-Buddha-Said.net/drops/II/The_1st_Noble_Truth_on_Suffering.htm
http://What-Buddha-Said.net/drops/II/The_2nd_Noble_Truth_on_The_Cause_of_Suffering.htm
http://What-Buddha-Said.net/drops/II/The_3rd_Noble_Truth_on_The_Ceasing_of_Suffering.htm
http://What-Buddha-Said.net/drops/II/The_4th_Noble_Truth_on_The_Way_to_Cease_Suffering.htm

Source: The Bundle of Threads. The Sutta-Nipāta 724-765
http://www.accesstoinsight.org/canon/khuddaka/suttaNipāta/index.html

Dual Consideration!