[Ali Imran]

According to the Bible, Jesus taught Paul the Christian faith through a revelation. Paul believed that Jesus taught him directly and personally. 

How did Jesus teach Paul?

• Revelation: Paul said that he received the gospel by revelation from Jesus Christ. 
  
• Study of the Word: Paul may have studied the Word of God for three years with Jesus. 
  
• Vision: Paul had a vision of Jesus during his first visit to Jerusalem. 
  

What did Paul say about his teachings?

• Paul said that he did not receive his teachings from any man, but from Jesus Christ. 
  
• Paul said that he received the gospel by the same means as the other apostles. 
  
• Paul said that he and the apostles agreed on the content of the gospel. 
  

Did Paul ever teach the Trinity? Did he ever say God is 3 persons? The answer is a definite no.

So quoting Paul doesn't solve your dilemma. If you want to insist God is 3 persons, you must reject the words of Jesus in John 17:3.