He gave charity on the basis that by doing so all his sins would be forgiven
Question

                MY question is, if someone lies to you by saying all ur sins we be removed and u will be like a new born baby if you give zakat every month. and u ask them for daleel and them give u some made up daleel(proof) and u do that act such as giving zakat every month. so even if that wasn't true and the person lied to u but u searched the the daleel and found it but actually the daleel wasn't true would all ur sins still be erased?

Im asking this question because this problem happens to many people.
Praise be to Allah.
      With regard to the one who deliberately tells a lie about 
      Allah and His Messenger, he is promised the punishment of Hellfire. It was 
      narrated that Abu Hurayrah (may Allah be pleased with him) said: The 
      Messenger of Allah (blessings and peace of Allah be upon him) said: 
      “Whoever tells a lie about me deliberately, let him take his place in 
      Hell.” 

    Narrated by al-Bukhaari (110) and Muslim (2). 

    Some of those who tell lies about Islam think that they are 
    doing something good if the lie is about virtues or encouraging people to do 
    good deeds or deterring them from doing bad deeds. 

    Al-Nawawi (may Allah have mercy on him) said: 

    When he forbade lying about him, the Prophet (blessings and 
    peace of Allah be upon him) did not differentiate between that which has to 
    do with rulings and that which does not have to do with rulings, such as 
    encouraging people to do good deeds, deterring them from doing bad deeds, 
    exhorting and so on. All lies about him are haraam and are major sins and 
    abhorrent actions, according to the consensus of those Muslims whose 
    opinions are qualified to be taken as part of consensus, in contrast to the 
    innovators of the Karaamiyyah group who falsely claimed that it is 
    permissible to fabricate hadeeths with regard to encouraging people to do 
    good deeds and deterring them from doing bad deeds, and they were followed 
    in that regard by many ignorant people who claimed to be ascetics or who 
    were classified as such by ignorant people. Their opinions, actions and 
    evidence are indicative of a great deal of ignorance and negligence, and are 
    the clearest proof that they have no knowledge of any of the basic rulings 
    of Islam. In their views, they have combined many flaws that are suited to 
    their foolish minds and corrupt way of thinking. They have gone against the 
    words of Allah, may He be glorified and exalted (interpretation of the 
    meaning): “And follow not (O man, i.e., say not, or 
    do not, or witness not) that of which you have no knowledge. Verily, the 
    hearing, and the sight, and the heart of each of those ones will be 
    questioned (by Allaah)” [al-Isra’ 17:36]. And they 
    have gone against the clear meaning of these mutawaatir hadeeths and well 
    known hadeeths which regard false testimony as a very serious matter. And 
    they have gone against the consensus of the scholars and other definitive 
    evidence that proves that it is haraam to attribute words falsely to any 
    individual, so how about the one whose words are part of sharee‘ah and 
    regarded as Wahy (Revelation)? If you look at their words, you will find 
    that they are telling lies about Allah, may He be exalted. Allah, may He be 
    exalted, says (interpretation of the meaning): “Nor does he speak of (his 
    own) desire. 4. It is only a Revelation revealed” [al-Najm 53:3]. 

    End quote from Sharh Muslim, 1/70, 71 

    What is based on an invalid foundation is invalid. Whoever 
    does any act of worship thinking that he will have a specific reward, then 
    finds out that that is not so, will not have the reward that he thought he 
    would get, because the issue of reward rests with Allah and does not depend 
    on weak and fabricated hadeeths. 

    This does not mean that he is sinning, because of the hadeeth 
    of Abu Hurayrah (may Allah be pleased with him) who said: The Messenger of 
    Allah (blessings and peace of Allah be upon him) said: “Whoever is given a 
    verdict that is not based on proper knowledge, his sins will be on the one 
    who gave him the verdict.” Narrated by Abu Dawood (3657) and Ibn Maajah 
    (53); classed as hasan by Shaykh al-Albaani in Saheeh al-Jaami‘, 
    6069. 

    So this person who gave charity will have a reward for his 
    charity, and charity is one of the causes of forgiveness for sins. But as to 
    whether all sins will be forgiven because of charity, Allah knows best. 

    Shaykh al-Islam Ibn Taymiyah said, when discussing innovated 
    acts of worship: 

    There is no doubt that the one who does them on the basis of 
    his own misinterpretation or because he is following (a shaykh or scholar) 
    will have one reward for his good intention and will be rewarded for his 
    deed inasmuch as it is in accordance with sharee‘ah, and whatever there is 
    of innovation in it may be forgiven on the basis that he tried to work out 
    what was correct or he was following someone and thus may be excused. The 
    same applies to whatever is mentioned of benefits of certain actions; 
    whatever benefit is gained may be because of whatever in his action was in 
    accordance with sharee‘ah, such as fasting, dhikr, reading Qur’aan, bowing, 
    prostrating and good intentions in worshipping and obeying Allah and calling 
    upon Him. And whatever it included of things that are disliked in sharee‘ah 
    may be forgiven by Allah because he based his action of what he thought was 
    best or he followed the example of someone else. And this is applicable to 
    everything that may be mentioned of the benefits of some innovated actions 
    that are disliked, but nevertheless this possible benefit does not cancel 
    out the fact that it is disliked and forbidden, and one should do what is 
    prescribed and has no innovation in it. 

    Iqtida’ al-Siraat al-Mustaqeem, 
    p. 290 

    And Allah knows best.