Peace be upon you.
The Oneness of God is explained by Ahmadiyya Promised Messiah Mahdi (upon whom be peace) he said that when a person obeys God, God never leave him. Do not think that God is unkind. The person who gives something in the path of God, receives much more than that. Fulfill Will of God. It is blessed act. Duality does not work.
The true root of Islam is Oneness of God. There should be nothing in human except belief in God, one should not taunt God and His Prophets, when one is in troubles. There should be no complaints in troubles. Troubles come because of self of human. God is not cruel.
It is true that Truthful people get troubles sometimes. Common people think these are troubles but actually these are not troubles, these are bounties in the disguise of trials, these increase the relation of Truthful person to God.
Those who have no relation with God, and their ill-deeds bring more trouble for them. They go astray. God increases the disease of their hearts. (Holy Quran 2:11)
Always be fearful of God and seek grace from God the Exalted. Do not be among those who cut relation with God. The person who connect to the Jamat established by God the Exalted,
He does not do favour to God. But blessing of God enabled him to join.
God is Capable to destroy a nation and create another nation. This age resembles with the era of Lot and Noah; instead of destroying the world with severe punishment, Allah the Exalted, with His grace and mercy, has wanted reform and He has established This-Movement (Ahmadiyya Muslim Jama'at). It is essential that our Jamat must bring in good changes in them. They must not become like those people who are low in love of God.
Hazrat Khalifa of Promised Messiah (may Allah be his Helper) reminds that it is very huge responsibility of Ahmadiyya Jamat that they should understand reality of Unity of God.
Reference: Friday sermon 16 may 2014 by Hazrat Khalifa tul Messiah (a..t.), 16 May 2014, alislam.org and mta.tv