Joy is something much deeper than your present emotional state
1 Thessalonians 5:16-19 (NIV) Be joyful always; pray continually; give thanks in all circumstances, for this is God's will for you in Christ Jesus. Do not put out the Spirit's fire;
Several times in the letters of the New Testament, the author gives a list of present, active, imperative commands. The verb tense in Greek tells us that each of these instructions is something we must do now. Right now and always we are to be joyful. It is a fruit of the Spirit. Joy does not mean that we are happy. How could you weep with those that weep and be happy? Joy is something much deeper than your present emotional state. It is the sense that comes when you believe that all is in the hands of your loving Father. Joy in difficult circumstances is a powerful testimony to the reality of your faith.
The next instruction is to pray continually. People often ask how this is possible. If you mean to isolate yourself and speak out loud to God without stopping, it is impossible. If it means to walk in constant heart to heart communion with God; it is the life of the Christian. Jesus should be our closest friend with Whom we share the moments of each day. A constant sharing with Him and listening to His voice will keep you walking in the Spirit.
God's will for us is that we give thanks in every circumstance. Everyone knows this is impossible without a radical commitment to walk by faith and not by sight. How can we thank God for loss and pain? It is only possible when we trust that He will work out everything for good. Giving thanks changes our perspective and cuts short the damage that the enemy intends.
The commands go on, but the last one for today is to not quench the Spirit's fire. The Spirit of God will cause you to share His passion for certain needs you come in contact with. Don't squelch that. Don't harden your heart to His leading. Go with it. He is encouraging you to step out and meet that need in His power. The reason we throw water on that fire is that we know it will cost us. Worrying about the cost is a carnal perspective. The godly perspective is that it is an opportunity to be an instrument of God, pleasing His heart, and laying up treasure in heaven.
Remember: Be joyful; pray always; give thanks; yield to the Spirit.