This question fits right in with God’s greatest commandment, found in Deuteronomy 6:4-5, to love our God with all of our being. Here is some guidance in how to bring that about from Scripture:
1) It goes without saying that we cannot love someone we do not know. Get to know God and what He has done for you. Before the command to love God is given in Deuteronomy 6:5, the statement is made, “Hear O Israel, The LORD our God is one LORD.” One aspect of this statement is that He is unique, and the better we get to know what He is like, the easier it will be for us to love Him with our whole being. This also involves getting to know what He has done for us. Again, before the first command is given in Exodus 20:3, God states what He had done for Israel in bringing them out of slavery in Egypt. Likewise, in Romans 12:1-2, the command to offer our lives as living sacrifices is prefaced with the word therefore--a word meant to remind us of all of the mercies of God toward us recorded in the previous chapters.
To grow in love with God, one needs to get to know Him. He has revealed Himself in nature (Romans 1), but so much more through His Word. We need to make daily Bible study a perpetual habit—as much a part of our lives as eating every day. We would do well to remember that the Bible is more than a book; it is truly God’s love letter to us, revealing His love for us through the centuries, especially through the ministry of Jesus Christ, His Son. We must read the Bible as a letter from Him, asking His Holy Spirit to speak to our hearts about what He wants us to glean from it that day. Memorizing important verses and passages is also essential, as is thinking of ways to apply what we learn (Joshua 1:8).
2) Follow Jesus’ example of praying constantly and consistently. When we examine the life of Jesus as well as that of Daniel and others who had a passion for God, we find that prayer was a vital ingredient in their relationships with God (even a quick reading of the gospels and the Book of Daniel reveals this). As with Bible study, prayer—sincere and open communication with God—is essential. You cannot imagine a man and woman growing in love without communicating, so prayer cannot be neglected without expecting one’s love for God to grow cold. Prayer is part of the armor against our greatest enemies (Ephesians 6:18). We may have a desire to love God, but we will fail in our walk without prayer (Matthew 26:41).
3) Walk closely with Him NOW. Daniel and his three friends chose to obey God and refused to compromise in even the food they ate (Daniel 1). The others who were brought from Judah to Babylon as prisoners with them caved in and are never mentioned again. When the Jewish prisoners of war had their convictions challenged in a far greater way, it was only these few who stood alone for God (Daniel 3 and 6). In order to ensure that we will be passionate for God later, we need to walk with Him now and begin to obey Him in the smallest tests! Peter learned this the hard way by following God “at a distance,” rather than identifying himself more closely with Christ before his temptation to deny Him (Luke 22:54). God says that where a man’s treasure is, there his heart will be also. As we invest our lives in God through serving Him and being on the receiving end of persecution for Him, our treasure will increasingly lie with Him, and so will our hearts (1 Timothy 3:12; Matthew 6:21).
4) Eliminate the competition. Jesus said it is impossible to have two masters (Matthew 6:24). We are tempted to love the world (those things which please our eyes, make us feel good about ourselves, and gratify our fleshly desires) (1 John 2:15-17). James says that to seek to embrace the world and its friendship is enmity (hatred) toward God and spiritual adultery (James 4:4). We need to get rid of those things in our lives (friends who would lead us the wrong way, things that take up our time and energy and keep us from serving God more fully, pursuit of popularity, pursuit of possessions, and the pursuit of physical and emotional gratifications). God promises that if we pursue Him, He will not only provide for our needs (Matthew 6:33) but will give us our desires as well (Psalm 37:4-5).
5) If straying, begin to do what helped you grow in love with God in the first place. It is not uncommon to have dips in a relationship. Peter dipped in his (Luke 22:54), and David dipped in his (2 Samuel 11), but they got up and pursued after God once again. John, in Revelation 2:4, states it is not a case of “losing” one’s love but “leaving” one’s love. The cure is to do the “first works,” those things that caused one to grow in love with God in the first place. This would include those items mentioned above. The first step in this is confession and receiving the forgiveness and restored fellowship that are the result of that confession (1 John 1:9). There is no doubt that God will bless the pursuit of a passion for Him and will glorify His name through it.