Abraham was a hundred years old when he had Isaac. Well passed his years of child conception. Now the lord was gracious to Sara as he had said, and the Lord did for Sarah what he had promised. Then she became pregnant and bore a son. Nothing met more to Abraham then his son.
Genesis 22:1 Sometime later God tested Abraham. He said to him, "Abraham!" "Here I am," he replied. And God said, "take your son, your only son, Isaac whom you love and go sacrifice him.
At the end of this story God stopped Abraham from killing his only son Isaac by giving and then testing Abrahams faith.
So in conclusion God is Loving and Merciful.