When you see your body wasted away through sickness, do not murmur against God, but say: 'The Lord gave, and the Lord has taken away; blessed be the name of the Lord' (Job 1:21). You are accustomed to look upon your body as upon your own inalienable property, but that is quite wrong, because your body is God's edifice.
John of KronstadtFirmly believe that the Lord is at all times everything to you. During prayer He is the power and the fulfillment in the Holy Spirit of each of your words. During pious conversation He is your living water, the ardent flow of your words at all times ? He is everything to you. Be free from care in the presence of your Lord. He has enclosed you with Himself upon all sides. He penetrates you wholly and knows all your thoughts, all your needs and inclinations, and if you live in Him with faith and love, then no evil shall befall you. 'The Lord is at hand; be careful for nothing' (Phil. 4:6).
John of Kronstadt...if you wish to get pure air into your room, or if you go for a walk in the fresh air, think of the pure and of the unclean heart. Many of us like to have pure air in the room (and this is an excellent habit), or are fond of walking in the fresh air, but they do not even think of the necessity of the purity of the spirit or heart (of, so to say, spiritual air, the breath of life); and, living in the fresh air, they allow themselves to indulge in impure thoughts, impure movements of the heart, and even impurity of language, and most impure carnal actions.
John of KronstadtAvoid duplicity, that is, do not let your heart be divided between attachment to God and attachment to earthly things, 'You cannot serve God and mammon' (Mt. 6:24); cling to God alone, put your trust in Him alone; for the Devil, by inciting us to duplicity, seeks himself to gain possession of our heart, which is single and indivisible.
John of Kronstadt