Pray in congregation; Say Amin when Imam does; Be sincere while praying; Repent sincerely for wrongdoings; Obey Allah's commands.

This hadith speaks to the power of prayer and supplication. It was narrated by Abu Hurairah that the Prophet Muhammad said that when an Imam leads a congregation in prayer and says "Amin", those who are praying should also say "Amin". If a person's "Amin" coincides with the "Amin" of the angels, then their previous sins will be forgiven. This hadith emphasizes how important it is for Muslims to pray in congregation and to say "Amin" at the same time as everyone else. It also shows us how powerful our prayers can be if we are sincere in them, as they can lead to forgiveness from Allah.

The lesson here for children is that they should always try their best to pray with others in congregation and make sure they say “Amin” at exactly the same time as everyone else so that Allah may forgive them for any wrongdoings they have done before. They should also remember that Allah is always merciful and forgiving, so even if their “Amin” does not coincide with those of angels, He will still forgive them if they sincerely repent for their mistakes.