For what religious, political, and commercial reasons was portugal interested in africa?

Portugal was originally only concerned about establishing forts and trading posts so as to protect the sea route to Asia. As time progressed, they began to see the benefit of establishing more permanent settlements. These permanent settlements would result in the expansion of their political influence. The exploration idea of God, Glory, and Gold also fit. The more permanent settlements would allow the Portuguese missionaries to also further expand and share their beliefs with the African Peoples.