In my walk with Christ, my love for Him has been strongest when I spent a lot of quality time in prayer. When we spend time with God we are feeding our spiritual nature, and in turn we desire more of God. If you want a love for Christ that is fire hot, start spending more quality time with Him by fasting and praying. Meditate on His Word (the Bible) throughout your day, and commune with other believers.
Absence from Jesus will not make your heart grow fonder!
“And you shall love the LORD your God with all your heart, with all your soul, with all your mind, and with all your strength.’ This is the first commandment.”