2Ti 1:7 For God has not given us a spirit of fear, but of power and of love and of a sound mind.
The opposite of fear is courage, the ability to face something that frightens you. The bedrock of courage is confidence, the feeling or belief that one can rely on something or someone. Courage is what allows you to act not because you’re not fearful, but rather act despite your fears. A soldier faces dangers with courage because he has confidence in his weapons and his ability to use them.
Paul wants to remind Timothy to fan the flame of these 3 gifts from above: #1 power, #2 Love, and #3 sound mind. Paul wants Timothy to use them as his means of overcoming his timidity: 2Co 10:4, ”For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds”. Alone, these gifts are inferior, in God they are mighty and powerful.
Perfect love is incompatible with such a self-punishing fear. Fear is natural to us all until love casts it out: 1Jn 4:18, ”There is no fear in love; but perfect love casts out fear, because fear involves torment. But he who fears has not been made perfect in love.” Then the spirit of a sound mind, or quietness of mind, a peaceable enjoyment of ourselves with renewed mind. It was through base fear that the evil servant buried his talent, and did not trade with it,(Mat 25:25). Now God has therefore armed us against the spirit of fear, by often bidding us fear not and reminding us of His equipping.