Concise Bible Dictionary:

The worship of God has been described as “the honor and adoration which are rendered to Him by reason of what He is in Himself, and what He is to those who render it.” It is pre-supposed that the worshipper has some relation with God, and that the order of service or worship is prescribed. The Israelites had been redeemed out of Egypt by God, and thus as a ransomed people could draw near to His appointed place to worship according to His order. The Psalmist could say, “O come, let us sing unto the Lord: let us make a joyful noise to the rock of our salvation.... for the Lord is a great God, and a great King above all gods.... O come, let us worship and bow down: let us kneel before the Lord our maker. For He is our God, and we are the people of His pasture, and the sheep of His hand” (Psa. 95:1-71O come, let us sing unto the Lord: let us make a joyful noise to the rock of our salvation. 2Let us come before his presence with thanksgiving, and make a joyful noise unto him with psalms. 3For the Lord is a great God, and a great King above all gods. 4In his hand are the deep places of the earth: the strength of the hills is his also. 5The sea is his, and he made it: and his hands formed the dry land. 6O come, let us worship and bow down: let us kneel before the Lord our maker. 7For he is our God; and we are the people of his pasture, and the sheep of his hand. To day if ye will hear his voice, (Psalm 95:1‑7)).
The worshippers could not enter God’s sanctuary in Old Testament times: their place of approach was its outer courts; and even the priests, except once a year, went no further than the holy place. All this is now changed: redemption has been wrought, the veil has been rent from top to bottom, God has come out, and worshippers, as priests, have boldness for entrance to the holiest. God has been revealed in the counsels of His love as Father, and the Holy Spirit has been given. The language of the Psalms therefore is hardly fitting for Christian worship, because of the nearness into which the believer is brought. In the millennium the people will not have access in the same sense: the true figure for the Christian attitude is that of the priest, not that of the people.
They that worship God must worship Him in spirit and in truth, and the Father seeketh such to worship Him (John 4:2424God is a Spirit: and they that worship him must worship him in spirit and in truth. (John 4:24)). They delight in what He is: they “joy in God,” and they love Him. To worship “in spirit” is to worship according to the true nature of God, and in the power of that communion which the Holy Spirit gives. It thus stands in contrast to worship consisting in forms and ceremonies, and to the religiousness of which the flesh is capable. To worship “in truth” is to worship God according to the revelation which He has been pleased to give of Himself. It would not therefore now be worshipping God “in truth” to worship Him simply as “a great God,” “our Maker,” and “a great King above all gods,” as in Psalm 95; for He has been pleased to reveal Himself in another light, even as “Father” to those who are His. They enter into His presence in the spirit of sonship, and in the sense of the love which has given them a place before Him in Christ, as sons according to His good pleasure: the sense of this love, and of the good pleasure of God in having us before Him in Christ, is the spring of worship. The Father and the Son are known, the Father’s will is that the Son should be honored as revealing the fountain of love, and the Son leading the hearts of the many sons into the Father’s love. Worship is thus distinguished from ascriptions of praise and thanksgiving; it is the homage of love (Rom. 8:1515For ye have not received the spirit of bondage again to fear; but ye have received the Spirit of adoption, whereby we cry, Abba, Father. (Romans 8:15)).

Strong’s Dictionary of Greek Words:

from 4314 and a probable derivative of 2965 (meaning to kiss, like a dog licking his master's hand); to fawn or crouch to, i.e. (literally or figuratively) prostrate oneself in homage (do reverence to, adore)
KJV Usage: