My trainer explains that physical strength improves only with active exertion past a stress point. You have to reach a place of exhaustion and then keep going.

When the Bible commands, “Be strong,” what does that mean? “Be on your guard; stand firm in the faith; be courageous; be strong” (1 Corinthians 16:13).

This is talking about spiritual strength. Note the word “faith.” In the original Greek language of the New Testament, this verb for the command “Be strong” literally says, “Be strengthened.” That’s a big difference!

Increasing spiritual strength is not like going to the gym. Increasing spiritual strength often means sweating and stressing less. Controlling less. 

Spiritual strength starts here: Your own personal strength that you manufacture (your own opinions, ideas, and abilities) is weak, fragile, and vulnerable. But your personal strength that God produces (divine truths accepted by faith, answered prayers, Spirit-led enlightenment about Scripture, salvation, good works of love, carrying the cross of suffering, resisting temptation) is resilient, courageous, and able to stand firm. 

Inner, spiritual strength starts from the outside. It is received from God by faith.

What situations fill you with fear? Confess how you have approached them too much with your own manufactured strength. Instead, trust in the spiritual strength promised by your Savior. Ask in prayer to “be strengthened” as he wants you to be. 

Then see what God can do. For you. In you. Through you.