The Roman soldier’s shield to which Paul refers was about four feet in length and about two and a half feet in breadth. It was usually made of wood and covered in leather. Unlike the other pieces of armour, the shield was flexible; the soldier could hold it above his head or in front of him to deflect arrows and javelins from hitting him. This is an interesting picture of faith, suggesting that faith is intended to be varied in its outworking. The Roman soldier would not have to protect his feet all the time or his chest or his head; he would use the shield to help protect a particular part of his body when a missile was coming near it. In a similar way, the Christian soldier uses his faith to help the particular blessing depicted in the other pieces of armour.
An important element of faith is its object. Paul’s concept of faith is faith in the living God or faith in Jesus Christ. Nor is it a mere intellectual faith, perhaps a conviction that the Christian religion is the true one. Rather this is a faith that involves the whole of a person. What are the various items that make up true Christian faith?
Faith is reliance upon Christ. The penitent sinner depends for salvation upon Christ alone. He commits his soul into Christ’s care and trusts in him for mercy. But this dependence is not limited to deliverance from the penalty of sin or to securing a place in heaven at the end of life. It also involves confidence in Christ for the present, for the ongoing battle against the devil. It looks to Christ’s power for deliverance from the crafty attacks of the enemy. Faith leans on Christ.
Accompanying this repentance and reliance, there is also in faith a resolve to follow Christ. This dedication is an expression of gratitude to Jesus for providing salvation. It reveals that in faith there is an inbuilt desire to serve the Saviour who has released the believer from the power of sin. This resolve is displayed in the battle against Satan. Faith is loyal to Christ.
A further element in true faith is a relish for Christ. Faith desires Christ, it focuses on him and delights in him. John Calvin, in his comments on Ephesians 3:17, says that ‘faith is not a distant view, but a warm embrace, of Christ, by which he dwells in us, and we are filled with the Divine Spirit’. This gives strength to one’s faith. Faith includes love to Christ.
Of course, faith is strengthened by meditation on the character of God, by applying to one self his great promises. Faith is nourished by consideration of the Bible. Faith in Jesus does not ignore information given in the Scriptures and it is instructed on how to express itself and on what to expect.