Yes, God, the ever-merciful and compassionate God, can be angry. His anger can even turn into fury and wrath. Just read the Old Testament, and you will have a good dose of vivid instances of this divine anger and wrath.
Which reminds us that anger is not bad after all. If God can be angry, we, who are his image and likeness, can be angry too. Anger has a place in our life. Except that we have to be most careful with it, since our anger can only be good and righteous only when we are truly identified with Christ. And given our current condition, that identification can only be at best tenuous.
To be sure, God's anger is not a lasting, much less, permanent feature. It's a passing emotion. As Sacred Scripture puts it, he is slow to anger, quick to forgive. His anger is just for a moment, but his mercy and compassion is forever.
Our anger should be like the anger of God. In the gospel, Christ showed this anger when he drove away those sellers and vendors who were desecrating the temple area. The same when he found a fig tree full of leaves but without fruit. (cfr. Mk 11,11-26)
We can clearly see that Christ was a man of passion also, which tells us that we should not be afraid of emotions and passions as long as we express them in the proper way. This training our emotions and passions will be a life-long process, and so we just have to be patient and sport about the whole affair.
We have to understand that to move toward our human and Christian perfection, not only should we be spiritual, but also we need to go passionate. That's simply because man is both spiritual and carnal, intellectual and emotional, with passion as the strongest expression of our feelings.
We have to overcome that partial understanding of our humanity that only highlights our spiritual aspect at the expense of our bodily dimension. Of course, it is also wrong to go the other way around, to stress the emotional at the expense of our spiritual development.
We have to take care of both dimensions to the highest degree possible. And in a certain sense, this reminder is urgent, since many so-called pious or religious people who try hard to effect some good transformation in individuals and society often concentrate on the spiritual and neglects the corporeal component of life.
The result is often dismal failure, wasting a lot of energy on an apostolic approach that perhaps can achieve some good effects that often do not last. These apostolic fruits fail to tackle the finer demands of our real life in the world.
Passions have to be properly cultivated. First of all, they have to be given due attention. They have often been considered, wrongly, as a drag in our human and Christian growth. They are left in the margins, at best.
They are never a hindrance. They are a necessary component, because love which is our perfection, while mainly an act of the will, a spiritual operation, cannot do away with our bodily dimension where love too has to be expressed.
I remember one point in the book, The Way, of St. Josemaria Escriva, founder of Opus Dei, that gives a relevant insight.
"You tell me, yes, that you want to. Very good. But do you want to as a miser longs for gold, as a mother loves her child, as a worldling craves for honors, or as a wretched sensualist seeks his pleasure? No? Then, you don't want to." (316)
If love has to be true love, it should not be confined only in the will and in the intellect. It has be go passionate, marshalling all the powers of our body–imagination, memory, feelings, the very use of our body, etcetera–to its employment.
Human and Christian love first has to be human before it can be spiritual and supernatural. It cannot be any other way. We would do violence to the nature of things if we understand it differently.
That's why, especially when dealing with kids and the young ones who often develop love first through feelings and the bodily aspects, we have to understand them and know how to make these feelings or passions conform to right reason and the requirements of faith and charity.
It's not a matter of repressing those feelings. It's a matter of educating them, revving them, in fact, to become passions and not just wimpy elements that we are ashamed to show and express.