To wage good warfare as Christians, we need encouragement (from God's word), the right equipment (faith and a good conscience), and knowledge about our enemies (how they became enemies, where they're headed, and the hope for them) if we hope to succeed.
Even when we are faithless, God is faithful.
I am not ashamed of the good news of Scripture – of the Christian gospel. For it is the power of God for salvation, to everyone who believes. The Bible is the very Word of God to us, and it is enough.