As believers, our identity in Christ is the primary focus of the enemy's attacks. In Ephesians chapter six, the description of the "armor of the spirit" is more than a lesson in spiritual warfare and protection, each aspect of the armor represents a mind-set. The "helmet of salvation" is protection over your mind; how you think; how you perceive yourself as a Christian. If the enemy can erode your confidence in God's grace (which includes his complete work on the cross to save you, heal you and give you peace), then it will be easy for you to doubt the love of Christ. Satan will lie and tell you that you are no longer saved because of your ongoing mistakes and failures.
The enemy attacked the minds of Judas, Thomas and even Peter during Jesus’ ministry. Then, because of their doubt, fear and ambition, they had moments of miserable failure. Obviously, we all have moments of failure because Satan is very astute in his ability to twist our own thoughts. He can make the truth so cloudy and obscure that we resort to our default setting, which is making decisions based on our emotions.
You must commit yourself to solidify the core of your faith by constantly reminding yourself of the truth. You are a weak human being that is subjected to the unfortunate reality that your mind, your memories and the lessons you've learned will fade away if they are not refreshed. You may pridefully say to yourself, "I’ve read that scripture before." But our ability to retain information and draw upon that knowledge fades over time, it's simply unavoidable.
So refresh the truth in your life with daily meditation in God's Word. Do not take lightly those Sunday sermons, or the Daily Bread devotional that you think is written for baby Christians. If you receive a scripture a day by email, or you take 15 minutes at lunch to read a book about the Christian life, try to absorb it and make it meaningful. Every little bit helps. It all matters. You'll be surprised how much more prepared you'll be for the attacks of the enemy by engaging in the daily study of truth found in the scriptures.