Friends:

For What do Men of good family go forth into Homelessness?

Once in Savatthi the Blessed Buddha said this:
Bhikkhus, whatever clansmen in the past rightly went forth into homelessness,
all did so in order to breakthrough to the Four Noble Truths as they really are.
Whatever clansmen in the future will rightly go forth into homelessness, all will
do so in order to breakthrough to these Four Noble Truths as they really are!!
Whoever clansman at present has rightly gone forth into homelessness, he has
only done so to breakthrough to the same Four Noble Truths just as they are!
What four?
The Noble Truth of Suffering,
The Noble Truth of the Cause of Suffering,
The Noble Truth of the Ceasing of Suffering,
The Noble Truth of the Way leading to the Ceasing of Suffering.
Whatever clansmen rightly went forth... will rightly go forth... have rightly gone
forth from household life into homelessness, all have done so in order to make
the breakthrough to these Four Noble Truths as they actually and really are.
Therefore, Bhikkhus, an effort should be mobilized to completely understand:
This is Suffering; This is the Cause of Suffering; This is the End of Suffering;
This is the way leading to the End of Suffering... An effort should be made to
understand, comprehend, penetrate, recognize & realize these 4 Noble Truths!

 

                          

Comments:
Only the perfect Buddhas breakthrough to, discover & explain these 4 truths!
Those who makes that effort and understands, shortens the Samsaric round...
Those who neglects that effort and ignores it, prolongs the Samsaric round...
Friends, it is by not understanding, by not penetrating the Four Noble Truths
that both you & I have cycled bewildered in birth-&-death for an eternity... 

More on these 4 Noble Truths (Cattari Ariya Saccani):
http://www.accesstoinsight.org/lib/study/truths.html
http://What-Buddha-Said.net/library/DPPN/wtb/s_t/sacca.htm
http://www.accesstoinsight.org/ptf/dhamma/sacca/index.html
http://What-Buddha-Said.net/drops/II/The_4_Noble_Truths.htm
http://www.accesstoinsight.org/lib/authors/thanissaro/wings/part3.html#part3-h-1
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_End_Suffering.htm

Source (edited extract):
The Grouped Sayings of the Buddha. Samyutta Nikāya. [V:415]
section 56: Saccasamyutta. Thread 3: Clansmen...