How do we know when God is opening a door or providing us an opportunity to serve Him? How do we know when an opportunity is from God? What can we expect when we step out in obedience and go "through the open door"? In his closing words to the Corinthian Church, the Apostle Paul gives us some insight into how he determines when an opportunity to minister or serve is from God and what we can expect by "walking through that door". From 1st Corinthians 16:5-12.