Spurgeon on assurance

Now, it is impossible for you to love God without the strong conclusive evidence that God loves you. I once knew a good woman who was the subject of many doubts, and when I got to the bottom of her doubt, it was this: she knew she loved Christ, but she was afraid he did not love her. “Oh!” I said, “that is a doubt that will never trouble me; never, by any possibility, because I am sure of this, that the heart is so naturally corrupt, that love to God could never get there without God first putting it there.” You may rest quite certain, that if you love God, it is a fruit, and not a root. It is the fruit of God's love to you, and did not get there by the force of any goodness in you. You may conclude, with absolute certainty, that God loves you if you love God. There never was any difficulty on his part. It always was on your part, and now that the difficulty is gone from you there is no more difficulty left. O let our hearts rejoice and be filled with great delight, because the Savior has loved us and given himself for us. So let us realize the truth of the text, “I am your husband.”

Charles Spurgeon, The Relationship of Marriage