I am convinced that people should celebrate 'the' (niepotr) Independence Day because 'thanks to' (to jest za bardzo po polsku - pomysl o czyms innym) it they remember about (brak przedimka) history (cos brak) their country and this is very important when it comes to national awareness ('withot' (ortog) it (przedimek) country cannot exist). Secondly, we should be 'a' (nie potrzeba przedimka przed l. mnoga) good patriots – love our Homeland, take care od 'their' (zle, tutaj mowisz o 'homeland' - ) history, remember about people who have 'been killed' (lepiej napisac 'died') for our freedom.
What is more, I think that during this day we 'also should' (zla kolejnosc slow) be grateful to God that we are alive and well. Additionally, people can sit back quietly and think and reflect on what has gone on in the world to keep 'their' (nie, to jest zle slowo) here and (cos brak) be proud of their ancestry.
It is essential to concentrate on the present and the future 'but' (to slowo tutaj nie pasuje, moze lepiej...in the words of GS...) George Santayana 'said' (niepotr) : 'Those who do not remember the past are condemned to repeat it'. and I 'deeply' (moze lepiej 'thoroughly') agree with his words.
Pamietaj o przedimkach (a, an, the). Jeszcze raz przeczytaj o nich.