Psalm 78: 10-17 (English Standard Version)
10 They did not keep God's covenant, but refused to walk according to his law.
11 They forgot his works and the wonders that he had shown them.
12 In the sight of their fathers he performed wonders in the land of Egypt, in the fields of Zoan.
13 He divided the sea and let them pass through it, and made the waters stand like a heap.
14 In the daytime he led them with a cloud, and all the night with a fiery light.
15 He split rocks in the wilderness and gave them drink abundantly as from the deep.
16 He made streams come out of the rock and caused waters to flow down like rivers.
17 Yet they sinned still more against him, rebelling against the Most High in the desert.
Psalm 78 recounts the Exodus story of Israel with the hopes that the generations following the psalmist would not be like the rebellious generation that was led out of Egypt. Notice the connection between verses 10 & 11. The reason Israel did not keep God's covenant & refused to walk according to his law was because they had forgotten the wonders that God had shown them.
Paul in his first epistle to the Corinthians and the Author of the book of Hebrews work with a similar paradigm as Asaph (The author of Psalm 78). Asaph declares that forgetfulness of God's salvation leads to covenant unfaithfulness. Likewise Paul and the author of Hebrews declare that the Exodus story of Israel was written for the instruction of the church that we might suffer a similar fate (1 Cor. 10 & Heb. 2).
If we are to be faithful to the New Covenant that God has gathered the church into through Christ we must not forget the wonderful works that God has performed on our behalf. This is why liturgy can be so helpful! When we participate week in and week out in the liturgy of the church (Praise, Confession, Communion, Benediction) we are continually reminded of the wonderful things God has done and continues to do on our behalf!
Food for thought.