Difference between complaint and gratitude?

Complaining is distrusting God, but gratitude is trusting in God

(Ref.: Exodus 17:3, 7).

Complaining is distrusting God.

As believers, quarreling and complaining in times of poverty

is testing God, asking, 'Is the Lord among us or not?'

(Exodus 17:3, 7)

In other words, complaining is disbelief in God.

Complaining is unwise.

It is unwise to complain about current circumstances

while citing good things from the past

(Ref.: Numbers 11:4-6).