Abram and Sarai followed God to Canaan - the land God promised to bless Abram in. The famine in Canaan lead Abram and Sarai to believe God wasn't able to care for them so instead of trusting Him they moved down to Egypt.
Before they got to Egypt, Abram told Sarai to tell the Egyptians that she was Abram's sister. That way, if one of the Egyptians wanted to marry Sarai because she was so beautiful, they wouldn't kill Abram. Sarai agreed and soon after they arrived, the Pharaoah himself took Sarai as his wife. Once again Abram didn't trust God to take care of him so lied in order to take care of himself.
Even though Abram and Sarai weren't trusting God, God still took care of them. He inflicted Pharaoh with a plague, and the truth came out about Sarai. Pharaoh was very angry with Abram and told them to take all their livestock and servants and leave Egypt.
Instead of trusting God's character, Abram focused on his circumstances. We learned that faith looks at who God is and trusts Him through impossible situations. God's character is the same and He's faithful to His promises regardless of how bad our circumstances are.