The need to believe

Abram and his wife was old. But they lacked faith. Abram and his wife wanted to help God. When a person wants to help God, then there will be issues.
Abram had a child with another woman. But this causes issues. Abram's wife hated Hagar. Hagar was the woman that give birth to a child for Abram.
Abram should have trusted God that he needed faith. God gave a child to Abram's wife so they needed to believe.
It is hard to have faith. God has the best plan for mankind. We need to ask God to increase our faith.
We need to realize that mankind is a sinner. We need to repent from our sins. Jesus died on the cross and arose from the dead. He did this because he was the perfect sacrifice. 
Then mankind needs to follow the Lord.

Genesis 16:1-4

  Now Sarai, Abram’s wife, had borne him no children. But she had an Egyptian slave named Hagar; ² so she said to Abram, “The Lord has kept me from having children. Go, sleep with my slave; perhaps I can build a family through her.”

Abram agreed to what Sarai said. ³ So after Abram had been living in Canaan ten years, Sarai his wife took her Egyptian slave Hagar and gave her to her husband to be his wife. ⁴ He slept with Hagar, and she conceived.
When she knew she was pregnant, she began to despise her mistress.