In 1 Kings 3:3 we read,
Solomon loved the Lord by walking in the statutes of his father David (HCSB).
What a clear and explicit statement of how one goes about loving God! These days, there is much confusion about this very point. There are those who would tell us, in near monkish terms, that one loves God by all sorts of personal disciplines and denials. Yet, we find no such things in the life of David—a life, in general, that is mentioned here as exemplary enough to hold up as an example. Of course, David had his faults—which are set forth in the Bible, but for the most part, he was willing to follow God’s commands, and repent when he failed to do so (there are no greater repentance psalms in the Bible than those written by him).
Don’t let anyone tell you that by following man-made restrictions and regulations one best loves God. Col. 2: 23 says it all:
Of course, they have a reputation for wisdom because of their self-imposed worship and supposed humility, and ascetic treatment of the body, but those things are of no value in keeping the flesh from satisfying itself.
God Himself has set forth the terms by which He is served in love. These, here, are termed “the statutes of David.” That does not mean that he set up his own statutes, but that he faithfully followed God’s (for the most part, that is—note the qualification about the high places in this verse).
If you want to love God, you will do as the Lord Jesus (Who never failed to do so) did—you will keep His commandments. Fundamentally, love is not a feeling. Love is giving: “God so loved the world that He gave”; “He loved us and gave Himself for us,” etc. The great commission is explicit: “teaching them to observe whatsoever I have commanded you.” These statements all reflect the same activity, namely, giving.
In the passage from 1 Kings, the word “walking” is the usual Hebrew expression for speaking of one’s lifestyle (or, as we also put it, how one conducts himself). So, John says in his two short epistles that he is delighted to hear how the reader’s children “walk in the truth.” That is, they live lives characterized by God’s truth. And, tying all of this together, he speaks in those letters of “love in the truth.”