“I am writing to you, fathers, because you know him who is from the beginning. I am writing to you, young men, because you have overcome the evil one. I write to you children, because you know the father.” 1 John 2:13 ESV
Belief in Christ is itself a gift from God. Before being saved you know nothing but darkness, you are fully susceptible to demonic influence because you cannot even see the light. In fact, the devil is described as an “angel of light” (2 Cor. 11:14). The unbeliever is deceived, literally blinded by the darkness, believing the darkness they are in is actually light.
When you receive Christ, God softens your heart and enables you to see through the darkness, “overcoming the [influence of the] evil one”. You are still susceptible to demonic influence, but you also have the knowledge, the power, to overcome the darkness through your faith. This power becomes stronger as you grow in faith, but it takes a lifetime of disciplined study of the Scripture.
Father, we thank you for the gift of faith. We thank you for enabling us to overcome the influence of demonic power. And we thank you for sending Jesus to suffer and die as our Savior. We ask you to enable us to have the courage to testify and proclaim Jesus, who brings the gift of eternal life to the world. Amen.