In Genesis 12, Abraham finds himself in Egypt with Sarah, worries that someone might kill him to take her, so instead he lets Pharaoh take her as his wife. Was this a good decision? In human terms it was: Abraham found himself in an impossible situation, and he needed to do whatever was necessary to survive so that he could continue on and see God’s promises fulfilled. Not only that, but by getting the blessing and support of Pharaoh, he was putting himself in a better position to make these promises come about.
This is a perfect example of how some people think they should operate within God’s providence. They understand that God has a plan and mission, and so they believe that they are called to do whatever needs to be done to advance that mission. This can be seen in ministries that focus on attraction rather than biblical faithfulness, because they need to attract people in order to minister to them. This can also be seen in any number of consequentialist arguments that justify a particular action because of how it is perceived to advance God’s plan, rather than whether the action itself is a good idea. This is also seen in the just-war arguments that support violent action in order to protect the innocent, or achieve a better outcome. In all cases, the error is the same: thinking that we as humans have to do all the work (often couched in terms of working hard and faithfully for God’s mission). The slightly more self-aware version involves thinking that we should TRY to do all the work, with the recognition that God will pick up the bits that we cannot do.
In essence, this is the complete reversal of how God wants us to respond to his sovereignty. He has the mission and he will bring it to fruition. Our job, as his servants, is to do the bits he has told us to do, in the certain knowledge that he is fully in control of the bigger picture. This is what Abraham was supposed to do, and God proved the point when he showed that he had a much better plan to advance his mission than the one that Abraham could come up with.
In short, Christians are not called to extemporise, we are called to be obedient and trusting.
More on providence in Genesis.