My relationship with Christ is sort of like riding a roller coaster. Sometimes I'm on fire for God, and sometimes I don't feel a thing. How can I stop this up-and-down ride?
Let me begin by saying that you can't always trust your feelings, because feelings have nothing to do with the facts of God's Word. Feelings come, feelings go. And feelings can fool you. Trust the facts, not your feelings.
One important fact is this: If you've trusted Christ, you're a Christian. Jesus said, "My sheep listen to my voice; I know them, and they follow me. I give them eternal life, and … no one can snatch them out of my hand" (John 10:27-28).
The Bible promises that "he who began a good work in you will carry it on to completion until the day of Christ Jesus" (Philippians 1:6). So we have to base our faith on God's sovereignty—what he has done and is doing in our lives—rather than on our feelings.
Scripture also says "if we are faithless, he will remain faithful, for he cannot disown himself" (2 Timothy 2:13). So even if you feel like your faith is fading, God remains faithful toward you. His commitment to you never changes.
Now, this is not to say that we should completely ignore our feelings. Sometimes our feelings are a pretty good indication of where we are spiritually. Our feelings might be trying to tell us we've sinned against God, or that we've put our relationship with God on the back burner. If either is the case, it's time to listen to your feelings. Scripture tells us, "Do not grieve the Holy Spirit of God" (Ephesians 4:30). When we sin, we "grieve," or disappoint, the Holy Spirit, who lives inside us to help us live the Christian life.
So, next time you don't "feel" like a Christian, do a gut check. Go to God and ask, "Have I sinned against you?" (See Psalm 139:23-24.) If you determine your bad feelings are a result of sin, ask God to forgive you. And ask the Holy Spirit to help you go on walking with God.
And think about those times when you're on fire for God. What are you doing during those times that gives you joy? You're probably reading your Bible, spending time in prayer, hanging out with Christians, going to Bible studies, telling others about your faith.
These are the kinds of things you need to do regularly and consistently. As you do, I think you'll experience fewer and fewer roller-coaster rides and that fire will burn stronger all the time.