The Promise Explained - What does it all mean?
"On my honour. I promise that I will do my best"
You will always try to do the best that you can because you think it is important to do so.
You may not always succeed, but you will always know if you gave it your best shot.
"to do my duty to God and to the Queen"
A duty is something you have to do, it is always best to try and do these things first such as homework, before someone tells you to. Your duty to the Queen, includes showing respect for her and what she stands for as our head of country. This includes keeping the laws of the land (or those of another you are visiting).
"to help other people"
Whenever you see someone who needs help you should offer assistance, don't let them struggle but see if you can help in any way.
"and to keep the Scout Law"
You will always do your best to obey the rules of the Scout Law"