It is very logical to have to suffer this assault. The devils have felt the grace of God entering our souls and they do not want Him to take us from their grasp. They then pull out all the stops to get us back into their hands and back on the path to eternal destruction. But, why does the Holy Ghost lead us into this? St. John Chrysostom suggests to us a few reasons. In Baptism, we have renounced the devils and all their allurements. These temptations serve to prove to the devils that we have truly renounced them. By our victory over them, we become ever more strengthened in our faith and the graces that we have received. We are humbled by our weaknesses which cause us to turn with greater fervor in pleading with God for His help. The devils are humiliated by being overcome by us.
If Jesus Christ was not beyond the temptations of the devils, we should in no way ever think that we should be free from them. There is a spiritual warfare going on for our souls, and we must fight if we wish to save them. If we never experience temptations, it should truly serve as a warning sign to us. The devils have no need to tempt those who are already securely on the path to their own destruction. In the sacraments, we have received the weapons to defend ourselves in this warfare. There would be no need for weapons or a defense if we were never to be attacked. "We have not received arms to stand at ease, but to fight." (St. John Chrysostom)
God also wishes to show us how much stronger we are now than we were before, but at the same time teach us that we must be prudent. While God knows how much we can endure and will not lead us into temptation that is beyond our own capacity to resist; we do not have that understanding and discretion. We must therefore never be so proud or bold so as to enter into temptation of ourselves. Such pride is certain to bring about our downfall. In leaning upon Christ we can do all things, but of ourselves we can do nothing.
We also learn through temptations of just how precious the graces we have received are. The greater the battle the more precious must be the object that is being fought over. The devils see and understand much more clearly than we do what a precious gift grace is; and it is for this reason that they pull out all the stops in tempting us away from it.
This Lenten Season we are called to do penance; and we are invited to examine our lives and conduct and renew our Baptismal promises. The stronger our resolutions are to live a life of grace, the more that we can expect to be assailed with temptations. This is the season for us to put forth our best efforts in the fight. To strengthen our souls for this struggle, we need to subdue our rebellious flesh. We do this simply through fasting and mortification. Some of the devils can only be overcome by prayer and fasting.
We are composite creatures with a body and a soul. The devils seek to destroy our souls, but they use our weaker side (the body) to focus the brunt of their assault upon. In our Lenten penances we train our bodies not to seek what is pleasurable to the body, but rather to obey the soul. While all that God has given us is good, many things are not expedient for us. Food is good for our bodies; but when our bodies become gluttonous and overindulge, the same food that is good and nourishing becomes harmful and destructive to us. We must therefore understand that everything is good when it is used properly according to the right reason of the soul; or more specifically, when it is used according to the Will of God. The devils assault our bodies by showing them the pleasure and goodness in the things God has given us and suggest that these things should be sought after and obtained at all cost — even in rebellion against God's Will and the right order of reason. We can fight against these temptations by training our bodies to obey our souls as we obey God. This training is best accomplished by the denial of legitimate pleasures to the body. It is no real sacrifice to deny ourselves that which is forbidden or unlawful. True sacrifice and training take place when we mortify ourselves even in that which is allowed. This is the surest way for us to come out victorious in the war for the very life of our souls.