The theme of Revelation 4-5 is the heavenly throne and the threat to that throne. The theme of Revelation 6 is the curses of the covenant. The word “curse” here does not mean profanity, it is a legal term that expresses the consequences of disobedience, of breaking the laws or norms of society or the kingdom of God. These curses were express in Old Testament texts like Leviticus 26:21-26, Deuteronomy 32:23-25, and 41-43, and Ezekiel 14:12-21. In the Old Testament these curses were described in terms of sword, famine, pestilence (contagious disease) and wild animals. The consequences of disobedience to the covenant were sometimes expressed as seven-fold curses (Lev. 26:21, 24). These curses of the covenant were sometimes executed in the Old Testament by four horses of different colors (Zech. 1:8-17; 6:1-8). So the four horses of the Apocalypse have a rich background in the Old Testament.
In the Old Testament the covenant was between God and Israel as a nation. The blessings and curses of the covenant occurred in a literal and national fashion, in other words, prosperity or adversity was visited on the nation of Israel as a whole. If the nation as a whole was faithful to God, the nation as a whole prospered in some very material ways (Deut. 28:1-14). If the nation as a whole was not faithful to God, the nation as a whole suffered war, famine, pestilence and poverty (Deut. 28:15-68). The covenant was between God and the nation of Israel. The curses of the covenant were the consequences of disobedience, and involved very material things.
In the New Testament, on the other hand, faithfulness to Israel’s covenant is determined in relation to Christ. As such they are more individual than collective, more spiritual than material, and more worldwide in implications than on any particular earthly nation. Those who are faithful to Christ, who are in relationship with Christ, are blessed in a spiritual sense (John 12:32; Acts 13:32-33; 2 Cor. 1:20). Those who reject Him, and are out of relationship with Him, are under the curse. They suffer the spiritual consequences of that condition; strife, division, ignorance of God and His Word, and spiritual sickness and rebellion. This appears to be the central theme of the four horsemen of the Apocalypse.