Why was Paul chosen to be a saint?

Answer 1

Paul worked for the lord after he was converted, whether in chains, prison, shipwrecked or in front of Roman council he spoke boldly, for example in chains and in prison. Paul says Rejoice and again I say rejoice.

Answer 2

He was first known as Saul then god struck him when he was on his way to damascus and literally told him he need to change so he is now known as Paul.