How is the ‘shield of faith’, described by Paul, both a protection and a weapon against ‘principalities, powers, the rulers of darkness of this world’, and ‘spiritual wickedness in high places’ (Ephesians 6:12)?
Our class teacher asked us a question like this in Gospel Doctrine a couple of weeks ago. After thinking about it, I came up with these reasons:
(a) Faith causes us to be humble. When you have faith in unseen things, you’re believing that something is true that you can’t sense with your mortal senses. You’re trusting in something more than, or beyond, yourself (this something being God). You’re saying that you are not the end point, the most important or wonderful; you’re not relying exclusively on yourself. This protects you from the danger of thinking you’re wise enough not to listen to something greater than yourself, or thinking that no such thing exists. It stops you from becoming like those Jacob warns against in that really excellent ninth chapter of second Nephi:
O that cunning plan of the evil one! O the vainness, and the frailties, and the foolishness of men! When they are learned they think they are wise, and they hearken not unto the counsel of God, for they set it aside, supposing they know of themselves, wherefore, their wisdom is foolishness and it profiteth them not. And they shall perish. (2 Nephi 9:28)
Believing that you know of yourself – without help from God – stops you from listening to the Spirit, and learning that which we’ve been sent here to learn. It squanders “the days of [our] probation” in following things that will do us no lasting good. In fact, those who lack Faith in things unseen, that are true, gradually lose their understanding of reality, and slide back until they have nothing left (see 2 Nephi 28:30 and 2 Nephi 9:42). The gate to the kingdom of heaven cannot be opened to them, because they don’t believe it exists, so they cannot see it. This is the importance of taking up the shield of faith – in Paul’s words, doing this “above all”.
(b) Faith leads to hope (Ether 12:4 – one of my favourite scriptures), because through it you believe in a better world, which causes you to act to prepare yourself and the present world for it, which makes you a better person. In other words, your faith in unseen things leads you to have hope in an unseen world, and to act accordingly. This hope also leads you to repent continually of your sins, because you can now see them, and you want to be ready for that better, unseen world. Such repentance adds to your hope – hope that you can make it, and that all is not lost. It’s a virtuous circle.
Faith, then, is the beginning of the other virtues (we can say also that courage is, but I believe that courage also comes from faith and hope). This is why it is a shield for us – it protects us from the ‘cunning plan of the evil one’ and gives us strength to change for the better.