Paul received personal revelation of the Gospel by the HolySpirit so that he had no doubts about -> the finished work of Christ Jesus, -> the boundless love that it demonstrated and -> the amazing Grace that it provided.
Unfortunately, humanity has a long history of perceiving the Creator God as mean-spirited and vindictive. So, Paul was basically saying that if your god does not supply all your needs then you may be worshipping another god or at least ignorant of the true and living One, Christ Jesus.
The riches of the LordJesusChrist are immeasurable, as is His love, as is His Grace. All that is needed to appropriate those riches is faith in His goodness and His Word.