"God is Spirit, and those who worship Him must worship in spirit and truth." {Jno.4:24} Jesus tells us that there are two basic elements to worship: spirit and truth. How does one worship God in spirit?
Pray with Spirit. What is the conclusion then? I will pray with the spirit, and I will also pray with the understanding ..." {1 Cor.14:15} Prayer is how we talk to God. One's heart must be put into our prayers. Jesus rebuked praying to be seen of men, Matt.6:1-5. He also rejects vain repetitions, Matt.6:7. Our prayer must be uttered from a true and sincere heart. Prayer that is not from this type of heart is unacceptable to God.
Sing with the Spirit. "...I will sing with the spirit, and I will also sing with the understanding." {1 Cor.14:15} Do you sing these song of praises to God in the proper spirit? Singing is a form of teaching, Col.3:16. Do you mediate on the words of the songs you sing? Do you really mean the things you say in song? "I Want to be a Worker," "A Soul Winner for Jesus," "Just As I Am," and "O To Be Like Thee" -- do you understand what you're singing?
Partaking of the Lord's Supper with Spirit. "Therefore whoever eats this bread or drinks this cup of the Lord in an unworthy manner will be guilty of the body and blood of the Lord. But let a man examine himself, ..." {1 Cor. 11:27,28} Do you remember what the bread and fruit of the vine brings to remembrance? Do you discern the Lord's body? In other words, do you focus and center your mind back to the cross where He died for you? Where is your mind when you take the Lord's Supper?
Give with Spirit. "So let each one give as he purposes in his heart, not grudgingly or of necessity; for God loves a cheerful giver." {2 Cor.9:7} Our giving is to come from the heart. What does this mean? Do you give because you want to or because you have to? Do you ever think what you could do with that money if you didn't give it back to God? Keep it! God doesn't need it and it's not helping you!
While it is important to do the things that God has commanded in worship if we leave out the "spirit" it will be vain worship! Are you worshipping God in spirit?