It is shocking for some to read Paul’s advice for slaves to obey masters. It sounds as though he is endorsing slavery. He is not. Within a context where slavery exists, he writes to slaves and tells them the best way for them to do God’s work is to willingly obey and do their work for God. A master and a community are more likely to be influenced by a cooperative slave than one who constantly needs to be disciplined. He tells the masters to be kind to their slaves. A kind master is more likely to positively influence a slave than a cruel one. Both the slave and the master need to serve God.
The armor of God is needed to do battle in the spiritual realm. We have enemies, but we have protection as we depend on God and what he has given us.