Selection from Arcana Cœlestia ~ Emanuel Swedenborg
They who have not been instructed about man's regeneration suppose that a man can be regenerated without temptation; and some that he has been regenerated when he has undergone one temptation. But be it known that without temptation no one is regenerated, and that many temptations follow on, one after another. The reason is that regeneration takes place to the end that the life of the old man may die, and the new heavenly life be insinuated, which shows that there must needs be a fight, for the life of the old man resists, and is not willing to be extinguished, and the life of the new man cannot enter except where the life of the old man has been extinguished. Hence it is evident that there is a fight on both sides, and this fight is a fiery one, because it is for life.He who thinks from enlightened reason can see and perceive from this that no man can be regenerated without a fight, that is, without spiritual temptation; and also that he is not regenerated by one temptation, but by many. For very many kinds of evil have made the delight of his former life, that is, have made his old life; and it is impossible for all these evils to be suddenly and simultaneously mastered, because they cling to the man very firmly, having been rooted in parents from time immemorial, and consequently are innate in him, besides having been confirmed in him from his infancy through his own actual evils. All these evils are diametrically opposite to the heavenly good that is to be insinuated, and that is to make the new life.
(Arcana Cœlestia 8403:2,3)