Ps 74 20Have regard for your covenant, because haunts of violence fill the dark places of the land." We are saved into the family of Abraham. God has made a covenant with us to bless and protect us. The Psalmist teaches that we are required to be faithful to the covenant. But this covenant is not  a two sided one. We are required to be faithful according to Gods grace. Our works are dependent upon being justified and redeemed by God. Where as from Gods side He puts Himself of display because He cannot accept our faulty covenant faithfulness. Christ became our representative in order for God to look at us as faithful. It is just as evil for us to speak of the covenant in our prayers as dependent upon our faithfulness as it is to be a covenant breaker. This is why the Psalmist forms his argument by petitioning God to be faithful according to His promises.