Romans 11:22 (NKJ) - Therefore consider the goodness and severity of God: on those who fell, severity; but toward you, goodness, if you continue in His goodness. Otherwise you also will be cut off.

This point is clearly illustrated through the evil servant in the parable of the talents.  He so feared his master that he buried his talents instead of using them as the master has commanded (Matthew 25:14-30).  As shown here, too much fear of His severity can prevent us from moving and the Lord considers it evil. 

King Saul did not fear the severity of God and His commandments when He decided not to wait on Samuel but to offer burnt offerings to the Lord himself.  This mistake costs Saul his kingdom (1 Samuel 13:8-14).  As shown here, a lack of fear of the severity of the Lord carried a great consequence.

Under the banner of grace, many people dangerously roll the dice and fail to observe the principles and commandments of God.  Romans 11:22 (see above) clearly warns us to continue in His goodness or we will be cut off. 

Fear prevents us from doing something but love causes us to do something. When you were a child, fear prevented you from doing things you shouldn’t such as hurting a sibling but love made you do things to please your parents such as making them a handmade Christmas card in school.  Knowing His severity keeps us safe and respects His authority and dominion over us, knowing His goodness allows us to love Him with all our heart, mind, and soul while loving our neighbors as ourselves.