Tazman,
bmerr here. John 4:24 says that those who worship God must worship Him in spirit (right attitude) and in truth (according to God's word - John 17:17). I believe this is a principle that has been in place since the beginning.
One's reverence for God and His Holiness is evidenced by one's obedience to God's word. Since God is no respecter of persons (Acts 10:34; Deut 10:17), He would not allow one group of people to approach Him with an irreverent attitude, while demanding reverence from another, so, the required spirit, or attitude of the worshipper has always been one of fear, or reverence.
On the other hand, God has, over the course or time, demanded different acts of worship of different groups.
From Creation to the Law of Moses, all of man was under what is called the "Patriarchal system", in which God spoke directly to men, and the Patriarch of the family acted as a priest (ie. Job 1:5; Ex 18:1). In Heb 11:4, we read "By faith Abel offered..." Since faith comes by hearing the word of God (Rom 10:17), we know that Abel acted in obedience to God's command when he offered his sacrifice.
Then God offered His covenant to the children of Israel (Ex 19:4-6) through Moses. Moses relayed God's offer to Israel, and Israel accepted (Ex 19:7-8). All the rest of humanity was still subject to the Patriarchal system of worship (Ex 18:27), though most of the nations had long since abandoned it. There were also provisions in the Law of Moses for Gentiles who wished to bring themselves under God's covenant with Israel.
Then, in the fullness of time, Christ came, and established His covenant with all of mankind, thus doing away with the Law of Moses, and the Patriarchal system (Heb 8:13, etc). From that point on, all men have been subject to the conditions of the New Testament of Jesus Christ, which we can look at later, if you like.
It's hard to be detailed, and short. Hope this can be a starting point.
In Christ,
bmerr