Jacob had two names, is why.  Not only interchangeably used, but what did Jacob mean, what did Israel mean ?  Using one name or the other became the giving of a message within a message.   Like selah in psalms .

<05542>

05542 celah seh- law 

from 05541; v; {See TWOT on 1506 @@ "1506a"} 

AV-Selah 74; 74 

1) to lift up, exalt 

1a) Selah 

1a1) a technical musical term probably showing accentuation, pause, interruption 

05541 calah saw-law 

a primitive root; v; {See TWOT on 1502} {See TWOT on 1503} AV-valued 2, trodden down 1, trodden under foot 1; 4 

1) to make light of, toss aside 

1a) (Qal) to make light of 

1b) (Piel) to flout, reject 

2) to weigh, balance 

2a) (Pual) to be weighed 

<05541>In context as the source word for <05542  >     <Scripture never says to make light of it. flount it, toss it aside, always to study it out.>

ALWAYS -  AV-valued - NEVER  trodden down or  trodden under foot what this Scripture of the Psalms is saying.

NEVER-  make light of, toss aside 

Never-  make light of 

NEVER -  flout, reject 

ALWAYS  to weigh, balance what is said in the balances of the Sancyuary / Plan of Salvation

ALWAYS-  to be weighed in their meanings as parts of the Plan of Salvation & Works & Doctrines & Mission of God's Words. 

So using "Jacob" may send a reference to his past, or what God has done to change him.  Israel does reference his victory over self.  

Hi Ed,

I thought Jacob meant deceiver

and when he was converted the name change and he was blessed by Jesus and renamed Israel the father of a nation

Genesis goes back and forth with the names

But once Saul is changed to Paul you don't see it fluctuate