If an innovator appears to be righteous, does that mean that his deeds and ‘aqeedah are sound?
Question

If an innovator appears to be righteous and he regularly does good deeds and offers all the prayers in congregation, does that mean that his good deeds and ‘aqeedah are sound? What is his position before Allaah?.
Praise be to Allah.Undoubtedly the correct stance is that every invented bid’ah should be rejected and denounced, and it should be pointed out that this is a departure from the straight path. We should not take this matter lightly. 
The Prophet (peace and blessings of Allaah be upon him) said: “Whoever does an action that is not part of this matter of ours will have it rejected.” Narrated by Muslim (1718). Al-Nawawi (may Allaah have mercy on him) said in Sharh Muslim (12/16): 
What this means is that such deeds are invalid and do not count. This hadeeth represents an important principle of Islam, and it is an example of the concise speech of the Prophet (peace and blessings of Allaah be upon him). It is a clear rejection of every innovation. This hadeeth should be memorized and used to demonstrate the invalidity of reprehensible actions and should be propagated as evidence against all innovations. End quote. 
The apparent righteousness of an innovator, or his striving in worship or good character, should not affect the shar’i view concerning bid’ah, because these things do not necessarily mean that his ‘aqeedah and deeds are sound.  
Firstly, we do not know what his end will be. The Prophet (peace and blessings of Allaah be upon him) said: “Deeds depend on what the last of them will be.” Agreed upon.  
Secondly, a Muslim may be guided to do some righteous deeds and deprived of doing others. There is a great deal of evidence to that effect, such as the following: 
1 – It was narrated from Sahl ibn Sa’d al-Saa’idi (may Allaah be pleased with him), that the Messenger of Allaah (peace and blessings of Allaah be upon him) met with the mushrikeen and they fought. When the Messenger of Allaah (peace and blessings of Allaah be upon him) went back to his camp and the others went back to their camp, there was among the companions of the Messenger of Allaah (peace and blessings of Allaah be upon him) a man who killed anyone (of the enemy) who got in his way. They said: No one has done better today than So and so. The Messenger of Allaah (peace and blessings of Allaah be upon him) said, “Rather he is one of the people of Hell.” A man said: I am going to follow him. So he went out with him; every time that man stopped, he stopped with him, and when he hastened, he hastened with him. He said: The man was badly wounded, so he sought to hasten his death. He put the handle of his sword on the ground and its tip in the middle of his chest, then he leaned [on his sword] and killed himself. The man went to the Messenger of Allaah (peace and blessings of Allaah be upon him) and said: I bear witness that you are the Messenger of Allaah (peace and blessings of Allaah be upon him). He said: “Why is that?” He said: The man who you said was one of the people of Hell and the people were astounded by that. I said, I will find out about him for you. So I followed him until he was badly wounded, then he sought to hasten his death.  He put the handle of his sword on the ground and its tip in the middle of his chest, then he leaned on it and killed himself. The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “A man may do the deeds of [the people of] Paradise, or so it seems to the people, although he is one of the people of Hell, and a man may do the deeds of [the people of] Hell, or so it seems to the people, although he is one of the people of Paradise.” (Narrated by al-Bukhaari (2898) and Muslim (112). 
Al-Nawawi (may Allaah have mercy on him) said in Sharh Muslim (2/126): This is a warning against relying too much on one’s actions. End quote. 
2 – It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: “The first one among the people to be judged on the Day of Resurrection will be a man who was martyred. He will be brought and Allaah will remind him of His blessings and he will acknowledge them. He will say, ‘What did you do with them?’ He will say: ‘I fought for Your sake until I was martyred.’ He will say, ‘You are lying; rather you fought so that it would be said that you were brave, and that was said.’ Then He will order that he be dragged on his face and thrown into Hell. And there will be a man who acquired knowledge and taught it, and he recited Qur’aan. He will be brought and Allaah will remind him of His blessings and he will acknowledge them. He will say, ‘What did you do with them?’ He will say: ‘I acquired knowledge and taught it, and I recited Qur’aan for Your sake.’ He will say, ‘You are lying; rather you acquired knowledge so that it would be said that you were a scholar, and you recited Qur'aan so that it would be said that you were a reciter, and that was said.’ Then He will order that he be dragged on his face and thrown into Hell.  And there will be a man to whom Allaah gave abundant wealth, and he gave all kinds of wealth. He will be brought and Allaah will remind him of His blessings and he will acknowledge them. He will say, ‘What did you do with them?’ He will say: I did not leave any way that You like charity to be spent but I spent charity for Your sake.’ He will say: ‘You are lying; rather you did that so that it would be said that you were generous, and that was said.’ Then He will order that he be dragged on his face and thrown into Hell.” Narrated by Muslim (1905) 
And there is another example which will show you that apparent righteousness does not necessarily mean that it is accepted by Allaah. 
3 – The Prophet (peace and blessings of Allaah be upon him) foretold the emergence of the Khaariji sect, who are people of bid’ah, and commanded us to fight them. He also told us that they would strive hard in worship. He said: “There will emerge among this ummah – and he did not say: from them – people in comparison to whose prayer you will regard your prayer as insignificant. They will recite the Qur’aan but it will not go any further than their throats. They will pass out of Islam like an arrow passes out of the prey.” Narrated by al-Bukhaari (6931) and Muslim (1064). 
The Messenger (peace and blessings of Allaah be upon him) described them as striving so hard in worship that even the Sahaabah would regard their prayer as insignificant when compared with these people’s prayer, but despite that he described them as passing out of Islam. 
A man may fall into bid’ah because of mistaken ijtihaad on his part, and he is not deliberately going against Islam and committing bid’ah. So we hope that Allaah will forgive him. 
Al-Dhahabi (may Allaah have mercy on him) said: 
If a major imam is mostly correct and is known for seeking the truth, and he has deep knowledge and is known to be intelligent, righteous, pious and keen to follow the Sunnah, he will be forgiven for his mistakes, and we should not regard him as misguided or shun him and forget about his good points. But we should not follow him in his innovations and mistakes, and we hope that he will repent from them. End quote. 
Siyar A’laam al-Nubala’ (5/271). 
The believer may have both good and bad points, so he is to be praised for his good points and criticized for his bad points, after advising and exhorting him.  
And Allaah knows best.