Dought and clear, - Repentance for Neglecting Acts of Worship.

I have neglected many rights of Allah in the past, such as prayers,
fasts, and zakah (payingpoor-due). Am I required to repeat themor
compensate for them?
Praise be to Allah.
As far as the five daily prayers are concerned, the preferred opinion
is that the repetition or compensation (or what is known as qadaa in
Arabic), is not obligatoryfor the reason that prayers are obligatory
ata particular time, and once that time has elapsed, there is no way
to offer them. However one ought to seek Allah'sforgiveness and offer
as many nawafil (voluntary prayers) as possible.
As for fasting-yes, if a person was a Muslim at the time they became
obligatory and he did not fast, then their performance is
required,accompanied by feedingof a poor Muslim for every day of fast
that was not observed duringprevious years. What is required is always
a day for a day-no more, no less.
Example 1: A person did not fast three days of Ramadan of the year
1400 A.H., and five days of Ramadan of the year 1401 A.H., all out of
negligence. He must now fast 8 days, and feed eight poor Muslims in
compensation.
Example 2: A girl reachedpuberty in the Ramadan of the year 1400 A.H.
but out of shame and modesty did not inform anyone of her
menstruation, and, rather, continued fastingsay for eight days of her
period. Thereafter, she repented. She would then be required to
redoeight days of fasting.
It may also be pointed out here that this is the predominant position.
A minority opinion is that the ruling for fasting is the same as that
for the prayers, i.e., there is no qadaa (making up) for fasting in
the case of a person who did not fast and did not have a valid reason
for not fasting.
As for he who did not offer the obligatory zakah, it is necessary for
a repentant to pay them for all previous unpaid years, for it is, from
one angle, Allah's right, while from another, the poor people's right.
(SeeMadaarij Al-Salikin for further details).
And Allah knows best.