First John, written ca. AD 86–95 in Ephesus, features three tests of genuine faith for discerning false teachers and assuring true saints:
1. Affectional (love)
2. Doctrinal (belief)
3. Ethical (obedience)

As we endure the trials and changes of this life, we can rest in God's neverfailing faithfulness. 

We should trust Jesus because he alone sustains and satisfies us.

In the midst of trials, we must trust Jesus to care for us.

Our faith in God and his promises must regularly be renewed. Especially in seasons and events of our lives that cause us legitimate fears and concerns. Psalm 46 is a song that has been sung by the people of God for centuries to renew and refocus their faith.