It is not uncommon, when we first embark on the spiritual life, that God in His compassion grants us a sense of His Love and His Presence, a spiritual warmth and joy. If this happens, let us thank Him with tears and rejoicing, staying firm in our efforts. However, it is important for us to understand that this feeling will not last. Invariably it will fade away within a short period of time, if it is not knocked away quickly by some tribulation in our lives, as sometime happens.
There are two reasons for this. First, this spiritual warmth was a free gift of God, a gift which we can do nothing to earn and which, as mere beginners on the spiritual path, we have done nothing to prepare ourselves for. God grants us, as it were, a taste of Himself (cf Ps 34:8), so that we might have at least an inkling of His Love and compassion, an inkling of what we are striving for, to serve as motivation for our journey. If this spiritual warmth were to continue, we would not struggle against sin and selfishness; we would make no spiritual progress.
The only time we make real spiritual progress is when we struggle for that progress, when we struggle to turn away from sin and autocentrism. The weightlifter increases the weights; the runner runs up hills. The mother puts her child down and backs up a bit, encouraging him to come to her rather than reaching out to pick him up—encouraging him to learn to walk.
With God it is the same. When He is near we pray, but our prayer does not yet have strength. It becomes strong when we continue to pray even though He has made Himself more 'absent'. Our virtue becomes firm when its practice is not rewarded by the praise of others, and even firmer when it is not appreciated or derided. Provided that we persevere.
We understand that our spiritual life will proceed in cycles. There will be times of spiritual warmth and peace, and there will be times of spiritual aridity, when God seems absent and we feel like we are climbing a spiritual sand dune. Even Christ Himself experienced a sense of the Father's absence on the Cross (ref Matt 27:46).
When spiritual warmth comes, we should rejoice in it and give thanks to God. When it departs, we should understand that this is both inevitable and beneficial, that it is time for our next period of struggle and growth. Let us continue our labors, not slacking off or letting our prayer become dry, confident that God will raise us up again when His Wisdom dictates. Our goal should be that the times of spiritual aridity will gradually become shorter, the descents from spiritual warmth slower and the returns quicker and sooner. When God wills, the cycle will be overcome.
May God grant us Wisdom!