Definition and Overview:
Spiritual warfare refers to the Christian concept of fighting against the work of preternatural evil forces. It is based on the biblical belief in the existence of spiritual realms and the ongoing battle between good and evil. Readiness in this context involves being prepared to engage in this battle through faith, prayer, and the application of biblical principles.

Biblical Foundation:
The concept of spiritual warfare is rooted in various passages throughout the Bible. Ephesians 6:10-18 is one of the most comprehensive texts on this subject, where the Apostle Paul instructs believers to "put on the full armor of God, so that you can make your stand against the devil’s schemes" (Ephesians 6:11). This passage outlines the spiritual armor, which includes the belt of truth, the breastplate of righteousness, the gospel of peace, the shield of faith, the helmet of salvation, and the sword of the Spirit, which is the word of God.

The Nature of the Battle:
The Bible describes the spiritual battle as not being against "flesh and blood, but against the rulers, against the authorities, against the powers of this world’s darkness, and against the spiritual forces of evil in the heavenly realms" (Ephesians 6:12). This indicates that the struggle is not physical but spiritual, requiring divine strength and wisdom.

Key Elements of Readiness:

1. Faith and Trust in God:
Faith is central to spiritual readiness. Hebrews 11:6 states, "And without faith it is impossible to please God, because anyone who approaches Him must believe that He exists and that He rewards those who earnestly seek Him." Trusting in God's power and promises is essential for standing firm in spiritual battles.

2. Prayer and Supplication:
Prayer is a vital weapon in spiritual warfare. Ephesians 6:18 encourages believers to "pray in the Spirit at all times, with every kind of prayer and petition." Persistent prayer aligns the believer with God's will and invites His intervention in the spiritual realm.

3. Knowledge of Scripture:
The Word of God is described as the "sword of the Spirit" (Ephesians 6:17). Knowing and applying Scripture is crucial for discerning truth from deception and for countering the enemy's attacks, as demonstrated by Jesus during His temptation in the wilderness (Matthew 4:1-11).

4. Righteous Living:
Living a life of righteousness and integrity protects the believer from spiritual vulnerabilities. The breastplate of righteousness (Ephesians 6:14) symbolizes the protection that comes from living in accordance with God's standards.

5. Community and Fellowship:
Engaging in fellowship with other believers provides support and accountability. Hebrews 10:24-25 emphasizes the importance of encouraging one another and assembling together, especially as the day of the Lord approaches.

Examples from Scripture:
The Bible provides numerous examples of spiritual warfare and readiness. In the Old Testament, Daniel's persistent prayer and fasting (Daniel 10) resulted in angelic intervention against spiritual forces. In the New Testament, the early church's reliance on prayer and the Holy Spirit empowered them to overcome persecution and spread the Gospel (Acts 4:23-31).

Conclusion:
Spiritual warfare and readiness are integral aspects of the Christian life, requiring believers to be vigilant, equipped, and reliant on God's power. Through faith, prayer, and the application of biblical truths, Christians are called to stand firm against the forces of darkness, advancing the kingdom of God in a fallen world.