Ephesians 6:12-13 is a passage from the New Testament of the Bible that states:

**Ephesians 6:12-13 (NIV):** “For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand.”

The Apostle Paul is traditionally considered the author of the Book of Ephesians. From an evangelical Christian perspective, Paul is a significant figure in the New Testament, credited with writing many of the letters (epistles) that form a substantial portion of the New Testament canon.

### Background on the Author:
1. **Identity**: Paul, previously known as Saul of Tarsus, was a Pharisee who initially persecuted Christians before having a transformative encounter with Jesus on the road to Damascus (Acts 9). After this encounter, he became one of the most important apostles in spreading the message of Christianity, particularly among the Gentiles.

2. **Context of Ephesians**: The letter to the Ephesians is believed to have been written during Paul’s imprisonment in Rome (around A.D. 60-62). The primary audience was likely the Christian community in Ephesus, a major city in Asia Minor, though it may have also been intended for surrounding churches.

3. **Themes**: In Ephesians, Paul discusses the nature of the Church, the fullness of the gospel, and practical Christian living. The passage in chapter 6 highlights the spiritual warfare believers face, emphasizing the importance of relying on God’s strength and armor.

4. **Spiritual Warfare**: The verses in question underscore the belief that Christians are engaged not just in physical struggles, but in spiritual battles against evil forces. This perspective encourages believers to equip themselves spiritually and remain vigilant against temptations and challenges.

5. **Practical Application**: For evangelicals, this passage serves as a reminder of the reality of spiritual warfare and the necessity of being spiritually prepared through prayer and reliance on God’s power. The imagery of the “armor of God” in the verses that follow encourages believers to adopt attributes such as truth, righteousness, faith, and the word of God as defensive and offensive tools in their spiritual life.

In summary, the Apostle Paul is the most likely author of Ephesians 6:12-13, and from an evangelical perspective, his teachings in this passage serve as a cornerstone for understanding spiritual battles and the importance of being spiritually equipped as followers of Christ.