From John Henry Newman: A Portrait in Letters, the letter written to Emily Forley, a young Catholic convert:
It is God’s mercy to bring us over difficulties. As time goes on, you may be cast down to find that your warmth of feeling does not last as it once was, and instead of it you may have trials of various kinds. Never mind; be brave; make acts of faith, hope, and charity; put yourself into God’s hands, and thank Him for all that he sends you, pleasant or painful. The Psalms and Saint Paul’s Epistles will be your great and abiding consolation.
“Rejoice with trembling.” I say all this, not as dissuading you from enjoying your present joy and peace, but that you may enjoy them religiously.
I repeat, God bless you, keep you, and direct you. Through His grace you have begun life well. May he give you perseverance.