What does it mean to abase and abound

The oxford online dictionary defines the word abound as follows:

abound: Exist in large numbers or amounts.
abound in/with Have in large numbers or amounts.

but, today I came across the following statement:

Generally in life you have to learn to abase and abound.

I am familiar with the word abase, it's meaning is apparent. But what does it mean to "learn to abound"? I certainly don't suppose it means to learn to exist in large numbers.

The phrase originates in the New Testament, Philippians 4:12-13 -

"I know both how to be abased, and I know how to abound: every where and in all things I am structed both to be full and be hungry." (King James "Authorized" version, c. 1611.)

This is generally construed to mean that the speaker (Paul) has experienced both want and wealth, both poverty and plenty.

The apparent oddity of the diction may stem from its 17th century origin. The translators sought to provide an accurate rendering of the scripture couched in what they hoped would be language felicitous to the ears of their contemporary audience.

(One's modern mileage may vary...)