What does your theory say about the guy in the train station asking me for money?
Any body suffers due to his or her own previous bad deeds. Suffering for God's mission is different thing. Jesus suffered for God's mission, His suffereing is for the goodness of humanity and not becuase of HIs previous sin and hence God Glorified Him.
But suffering of ordinary people not for God's mission is due to thier own previous sins only.
The person now begging on the street has lavishly spent money in the previous birth to undeserving. To teach him the lesson now he is suffering and looking for the money he has wasted.
Another example i will give you:A poor peon- A begger- Deceased rich man
A poor peon is the greedy fellow in the previous birth, who earned wealth for generations through businesses and corruption without any sacrifice.
A beggar searching for money is a person, who wasted the money in lavish manner by giving to undeserving people.
A life long deceased rich fellow is a rich person in the previous birth, who spent all the earnings for his selfishness only.
Another example for suffering due to ones own bad deeds:
Donation is very dangerous like double edged knife. Donating to undeserving persons is very big sin and not mere wastage. Today, if you see the feast of a marriage function, you will find most of the plates after feast are full of food items leftover. When you throw this food, it becomes a source for bacteria and virus, which may harm even good people in the society. Thus, the people, who have thrown the food, become sinners. The owner of feast, who gave this expensive food to them is also another sinner and will be punished by the divine law.
Both doer and promoter are equally punished (Kartha karaiyitaa chaiva...). Finally the married couple is also affected. Veda says that even a single particle of the food should not be wasted (Annamna parichakshita...). Once, in a function, the people were wasting food and the beggars on the other side were searching for the food in the leaves thrown away after the feast.
One devotee asked Bhagavan Shri Satya Sai Baba like this, “O Swami! What is this! In your creation I find people throwing food on one side and people searching for the thrown food on the other side”. Bhagavan Baba replied “Those beggars were also rich in the previous birth and threw the food like these rich people. They are now born as beggars and are searching for the food thrown by them in the past”. Therefore, the minimum eligibility of the receiver of food is: not to throw even an iota of food.