Why is the judicial independence so important under our system of government?

Judicial independence is tantamount to our democratic system of government because it means that courts should be independent from the government; this is to say that courts are therefore immune to pressures or other influences of the rest of the government, specially the executive branch.

Judicial independence allows judges to give rules impartially. Things like pay, security of tenure and so on gives the judges confidence that their job is not at stake when they judge honestly and impartially though the judgment pronounced may not be to some party's liking. The judiciary cannot be under the influence of the legislature nor the executive or then their judgments will not be fair.