The terms consolation and desolation are used by Ignatius de Loyola in his Spiritual Exercises. I’ll let Ignatius define the terms, though they are briefly presented and not in their fullness.
I call it consolation when some interior movement in the soul is caused, through which the soul comes to be inflamed with love of its Creator and Lord and when it can in consequence love no created thing on the face of the earth in itself, but in the Creator of them all…Finally, I call consolation every increase of hope, faith and charity, and all interior joy which calls and attracts to heavenly things and to the salvation of one’s soul, quieting it and giving it peace in its Creator and Lord. 
I call desolation all the contrary of the third rule [regarding consolation], such as darkness of soul, disturbance in it, movement to things low and earthly, the unquiet of different agitations and temptations, moving to want of confidence, without hope, without love, when one finds oneself all lazy, tepid, sad, and as if separated from his Creator and Lord. 
Remembering that the Exercises were written between 1522 and 1524, the words “consolation” and “desolation” are translations of Latin terms which were translations of Spanish words for Ignatius wrote in Spanish, we can gather that Ignatius did not use them in the manner in which we use them today. Our dictionaries sum it up in the one word “comfort.” Desolation is grief, sadness, and ruin. As I write, I will be using Ignatius’ definitions.
Now it seems to me that the modern-day Church has become enamored with consolation. We want things that are going to feel good, to help us put last week behind us and “fill us up” for the week to come. However, this process can be done through many different means. For instance, attending a concert or play, watching a movie, or going to a sporting event. There are other ways of trying to get the “feeling” of consolation such as drinking alcohol or smoking marijuana. None of these things have anything to do with the Church, worship, or God.
I am empathetic to this weekly attempt to get a spiritual high. I have participated in some churches in my life seeking the same thing. But the high one gets from worship, if one gets anything at all, is very short-lived. It dissipates like smoke in the air. I am also empathetic with pastors who feel the pressure from his or her congregation to be as charming, charismatic, and entertaining as those they hear on the radio or see on television.
However, feeling good is not at all what worship is about. In fact, if worship is properly addressed to God, we might well feel humble, ashamed, and thankful for our salvation. Look again at the definition, “every increase of hope, faith and charity, and all interior joy which calls and attracts to heavenly things and to the salvation of one’s soul, quieting it and giving it peace in its Creator and Lord.” Consolations call us to heavenly things, to salvation, and it is peacefully quiet. Try to accomplish the latter in our contemporary theater-like churches and highly paced music and worship.
Ignatius gives us instruction for times of consolation:
Let him who is consoled see to humbling himself and lowering himself as much as he can, thinking how little he is able for in the time of desolation without such grace or consolation. 
Why? Because in this life, consolation is fleeting. We even have the power to psychologically create feelings of consolation that are not consolation at all. They are emotional tricks.
Jesus took Peter, John, and James up a mountain to the top (Matthew 17). When they reached the top, they saw Jesus transfigured. The Greek word is where we get the word metamorphosis. Jesus was changed, and the change was so the three disciples could see him in his glorified state. Now that’s consolation! Peter was so excited that he wanted to stay there. He never wanted to leave the consolation of Jesus glorified. The voice of God interrupted Peter in his excitement. They were not to stay there in their mountain-top high. They had to go back down the mountain and work. And that is where desolation does its work.
I will continue this in my next post.