All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Your statement to your wife “if you do not pray, you are divorced” is a divorce conditioned on not praying, so if you mean by this that if she abandons any of the five daily obligatory prayers, and your wife did not pray even one of them, then she becomes divorced because she did not pray it and your condition applies to her. However, if you mean if she completely abandons the prayer, then she does not become divorced unless she completely abandons the prayer.
As regards your statement that you do not want divorce, then this contradicts your statement that you were serious when you mentioned your conditional divorce. In addition to this, the wording that you mentioned is a clear statement of divorce, and the scholars stated that clear statement of divorce leads to divorce taking place even if the husband did not intend it whether he was joking or serious as Abu Hurayrah narrated that the Prophet said: “There are three things if they are done seriously they are valid and if they are done in jest they are also valid: marriage, divorce and taking back a wife (to marital bond) after divorce.” [Abu Daawood, At-Tirmithi and Ibn Maajah]
With regard to whether or not you may cancel this condition before it happens, then Shaykh Ibn ‘Uthaymeen was asked: “Can the divorce that is conditioned on doing something be cancelled if he (the husband) waives the condition he put for divorce?, and he answered saying: “The correct opinion is that it can not cancelled by that.” Therefore, waiving your condition is of no benefit, and in case the divorce is not the third divorce and the condition which you laid down for divorce happens, then divorce will take place as a revocable divorce, in which case you may take back your wife as long as her waiting period has not expired.
However, you should know that a husband must order his wife to perform the prayer and admonish her strongly about that and if she does not pray, he should divorce her. Rather, it is an obligation to divorce her according to the correct view of the scholars . Shaykh Ibn Taymiyyah was asked about a person whose wife does not pray "Must he order her to perform the prayer, and if she does not pray must he separate from her or not?" He answered: “Yes, he should order her to perform the prayer and it is an obligation upon him to do so; rather, he is obligated to order any person whom he can order if other people did not order him/her to do so, and Allaah Says (what means): {And enjoin prayer upon your family [and people] and be steadfast therein.}[Quran 20:132] Allaah also Says (what means): {O you who have believed, protect yourselves and your families from a Fire whose fuel is people and stones.}[Quran 66:6] Moreover, the Prophet said: “Teach them (your children) and discipline them.” However, he should incite her (his wife) to do this willing to do so in the same manner he incites her to do for himself what he needs. If she insists on abandoning the prayer, then he should divorce her and this is an obligation upon him according to the correct opinion, as the person who abandons the prayer deserves punishment until he performs prayer according to the view of all Muslims.”
Allaah Knows best.