They narrow their selection to two men and they roll the dice. Luke record the Holy Spirit overwhelming these me at Pentecost. Since you say he 'self-appointed himself' I assume you reject the historicity of Luke's documents. Peter later writes that Paul's letters are Scripture. The words in his writings lead people into lawlessness.
People are already lawless.
What we need is someone to lead us out. JHVH reveals His Law to silence us. The Law is good. Paul has a very high view of Torah. Let me first say that it is not a situation where I can lead you to understand the spell cast upon millions through the writings of Paul.