Islam requires both faith and action. Therefore, people are required to say their ritual prayers as a matter of faith.
So, when standing in prayers they remember Allah but this verse tells Muslims to remember him after they finish praying. How then can we remember Allah after we have finished praying?
That is by putting into practice what Allah tells us. If a person is a businessperson and finds that they can make a profit by telling a lie they should remember Allah who has commanded us to speak the truth. This applies to all our daily actions and practices. In fact, our daily worship is closely related to the lesson in this verse of the Holy Quran. We begin our day by praying, we break our work or business during the day by praying, we break the time when we are relaxing to pray and the last thing at night we is to pray. In the intervening period we remember that although we are not praying we still remember Him by doing as He says.