Honour Thy Parents
In Islam, it is obligatory for us to show kindness, respect and obedience to our parents. In fact, kindness and obedience is so strongly emphasized that Allah (SWT) has linked showing gratitude to one's parents with showing gratitude to Allah (SWT). The Quran makes it clear that we must honour our parents, appreciate their sacrifices and efforts for us, and do our best for them. This is required regardless of whether they are Muslim or not. It is the duty of the sons and daughters to pray for the forgiveness of their parents after their death.
According to Prophet Muhammad (PBUH), if a person obeys his or her parents, attends to their needs and keeps them happy and comfortable, he will attain paradise. But, if he is disrespectful and rude to them, offends them by ignoring their needs and feelings or causes them grief in any manner, his place shall be in Hell. The time that parents need to be looked after most, is in their old age. The best way of pleasing Allah (SWT) is to serve your parents devotedly. It is also one of the easiest ways of attaining paradise.
The sahaba say that a man came to Prophet Muhammad (PBUH) and asked him if he could join the military. The Prophet (PBUH) asked the man "Do you have a mother?" The man replied "Yes!" The Prophet (PBUH) looked at the man and told him "Stay with her, for paradise lies under the feet of the mother."
“Thy Lord hath decreed that ye worship none but Him, and that ye be kind to parents. Whether one or both of them attain old age in thy life, say not to them a word of contempt, nor repel them, but address them in terms of honour. And, out of kindness, lower to them the wing of humility and say; My Lord! Bestow on them thy mercy even as they cherished me in childhood” — Holy Qur'an (17:23)