The waiting game (Part 1?)

I read the story of Sarai this week (Genesis 12-17). God spoke to Abram and said "I will make you a great nation. I will bless you." The scripture says nothing about his wife Sarai, other than Abram took her along with all their possessions and set out for Canaan. Along the way, God said to Abram "I will give this land to your offspring."

We learn that Sarai, has not been able to conceive a child. God had made a promise to Abram, but never mentioned his wife. I'm sure that it was a given that God would bless Abram and Sarai with a child, but why didn't he mention her?

Sarai, gets tired of waiting and takes the situation into her own hands. This is where it goes downhill quickly! She gives her maidservant to Abram as a wife, so that he can have children. It was a custom at that time, for men to adopt servant children as heirs, if they didn't have children of their own. Hagar conceives a child. Animosity and tension builds between the two women.

Again, the Lord appears to Abram and says Hagar's child is not the one he will bless. There is another child that will come from Sarai (who is now 90 years old) and this child will be the son that God intends to bless and make fruitful.

So, Sarai (now called Sarah) messed up because she didn't wait on God. She didn't wait for Him to fulfill the promise that he made with Abram (now called Abraham).

I have been thinking about my life and the times I have waited on God, either patiently or impatiently. There are also plenty of times that I have not waited. I can completely identify with Sarah. God made a deal with Abraham and never directly mentioned who the mother would be. So, maybe He didn't mean her? She was in a holding pattern and felt like she needed to do something. She didn't want to be the one standing in the way of her husband's blessing. There have been opportunities in my life that came up, and I wonder "am I supposed to move on this or do I wait on God"? There have been times I have stepped out on faith, things don't go well and I wonder "was I wrong for moving ahead"?

In The Feminine Soul by Janet Davis, she speaks to this topic. "At times our exclusion from God's work is as real as Sarai's infertility. In those times it is far easier to draw false conclusions, to blame, and to settle for less than it is to persevere in our vision, struggle, and unfulfilled desire. It is critically important to own that we, like Sarai, have sometimes been the first ones to give up the vision of our contribution to the whole of the church, unwilling to remain engaged in the difficult and painful struggle."

It is easier to think, than wait. I start thinking instead of waiting. I think myself right out of the plan that God had prepared. It can be so painful! Things happened between Sarai and Hagar that would have never occurred if Sarai had only waited.

I am not finished with this study. Here are my questions:
How do we know when to wait?
How do we know when to step out on faith?
Why didn't God mention Sarai/Sarah until the final covenant?