Why is it Protestants don’t know 1 Tim 2:5? It has ZERO to do with intercessory prayers. Paul is speaking of covenant mediation.  μεσίτης  is used 6 times and 100% of the time it refers only to covenant mediation. Paul is saying only Christ can die to mediate the new covenant and serve as ransom.  

That said, Paul says EVERY member of the body of Christ is to be an intercessor for all men. Paul and James say to seek such intercession. John says such intercession occurs in heaven as believers there take prayers of saints on earth before Christ.  It’s quite biblical.