'Vulnerable' means capable of being attacked, getting hurt or wounded. We constantly face the possibility of coming under attack from Satan (1Pe.5:8). But even if he were to leave us alone, the strong desires that are in our old, fallen nature or flesh are sufficient to form sources of temptation to sin (Jas.1:14,15). These sinful desires can come up in different situations, whether we are alone by ourselves, interacting with people, or facing challenges or attractions from the world around us. In other words, with such a variety of attacks coming up against us, all of us are so vulnerable that it is surprising if we don't fall now and then, especially when the temptation comes from unexpected quarters or when we least expect them. Growing in spiritual maturity is to become more discerning and stronger to resist when temptations hit us.
When we look at the various parts of the armour God wants us to have in order to defend ourselves from the attacks that come from different directions, we can see that it is not easy to be so careful that we don't get hurt in any way. Actually, all of us are very vulnerable. But by defining temptations or failures to different levels, we can imagine that we have victory, but we need to go and look at deeper levels, as when we peel onions. For example, if we think of anger as when we hit out physically at others and we are able to stop that, what about anger coming out in words, or in our thoughts and attitudes? Simply because we don't commit adultery with anyone physically, can we ignore the lustful thoughts that can be going on inside us? In the same way, are we in the habit of ruling out jealousy, covetousness, greed, complaining, unforgiving attitudes, judgmental attitudes, superior feelings, etc.?
One of the most dangerous steps to take in this context is to consider only our external behaviour, as the Pharisees did. Then we may think we are very holy or spiritual, when God thinks of certain things in us as 'stinking' (Mt.23:27). We may also not be aware that some of the people also can notice this stink, and are keeping quiet out of politeness! Worse still, when someone tries to mention it to us, we 'shoot them down'! Do we really want to continue to 'walk in darkness' where we resist light from coming into our hidden areas and exposing what is producing this stink (Jn.3:19,20)?
We must not forget the fact that our whole life is open before God, even if we try to make ourselves believe no one knows certain things (He.4:12,13). If we really want to walk in the light before Him, we have to let the light come in more and more and expose us before God. He is not going to be judgmental, but waiting to sanctify us in our body, soul and spirit, entirely (1Th.5:23). It was for that reason that He sent His Son to us. Let us train ourselves to open ourselves fully before Him and to listen to what He has to say (Jas.4:8-10). He wants to bring us cleansing and healing in every way.