1. Teach them about Allah Almighty using His Names and Attributes. Be sure to make them _experience_ this knowledge, and avoid making their relationship with their Lord a body of _theoretical knowledge_ void of any understanding and action.
2. Frequent the following dua:
رَبَّنَا هَبۡ لَنَا مِنۡ أَزۡوَ ٰجِنَا وَذُرِّیَّـٰتِنَا قُرَّةَ أَعۡیُنࣲ وَٱجۡعَلۡنَا لِلۡمُتَّقِینَ إِمَامًا
“Our Lord, grant us from among our wives and offspring comfort to our eyes and make us an example for the righteous.”
3. Strategically place them in efforts/projects that are beloved to Allah Almighty, for this will make them from the righteous, and Allah Almighty protects and takes care of the pious and righteous.
The pious before us would say: “We made our children work for Allah, and Allah took care of their dunya (worldly life) and their aakirah (hereafter)”.
May Allah preserve us and our children in His obedience, and gather us with our children in the Highest paradise. Ameen.
Shaikh Sajid Umar