Question: "What is the meaning of Christian worship?"
Answer: The meaning of the New Testament Greek word most often translated "worship" (proskuneo) is "to fall down before" or "bow down before." Worship is a state (an attitude) of spirit. Since it's an internal, individual action, it could/should be done most of the time (or all the time) in our lives, regardless of place or situation (John 4:21). Therefore, Christians worship all the time, seven days a week. When Christians formally gather together in worship, still the emphasis should be on individually worshiping the Lord. Even in a congregation, participants need to be aware that they are worshiping God fully on an individual basis.
The nature of Christian worship is from the inside out and has two equally important parts. We must worship "in spirit and in truth" (John 4:23-24). Worshiping in the spirit has nothing to do with our physical posture. It has to do with our innermost being and requires several things. First, we must be born again. Without the Holy Spirit residing within us, we cannot respond to God in worship because we do not know Him. "No one knows the things of God except the Spirit of God" (1 Corinthians 2:11b). The Holy Spirit within us is the one who energizes worship because He is in essence glorifying Himself, and all true worship glorifies God.
Second, worshiping in spirit requires a mind centered on God and renewed by Truth. Paul exhorts us to "present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship. Do not be conformed to this world, but be transformed by the renewal of your mind" (Romans 12:1b, 2b). Only when our minds are changed from being centered on worldly things to being centered on God can we worship in spirit. Distractions of many kinds can flood our minds as we try to praise and glorify God, hindering our true worship.
Third, we can only worship in spirit by having a pure heart, open and repentant. When King David's heart was filled with guilt over his sin with Bathsheba (2 Samuel 11), he found it impossible to worship. He felt that God was far from him, and he "groaned all day long" feeling God's hand heavy upon him (Psalm 32:3,4). But when he confessed, fellowship with God was restored and worship and praise poured forth from him. He understood that "the sacrifices of God are a broken spirit; a broken and contrite heart" (Psalm 51:17). Praise and worship toward God cannot come from hearts filled with unconfessed sin.
The second part of true worship is worship "in truth." All worship is a response to truth, and that which is truth is contained in the Word of God. Jesus said to His Father, "Thy word is truth" (John 17:17b). Psalm 119 says, "Thy law is truth" (v. 142b) and "Thy word is true" (v. 160a). To truly worship God, we must understand who He is and what He has done, and the only place He has fully revealed Himself is in the Bible. Worship is an expression of praise from the depths of our hearts toward a God who is understood through His Word. If we do not have the truth of the Bible, we do not know God and we cannot be truly worshiping.
Since external actions are unimportant in Christian worship, there is no rule regarding whether we should sit, stand, fall down, be quiet, or sing praises loudly while in corporate worship. These things should be decided based on the nature of the congregation. The most important thing is that we worship God in spirit (in our hearts) and in truth (in our minds.)