In my view, any of the religions teach mankind to be good. Does that mean that no matter which religion mankind follows, as long as they are sincere and commit no evil deeds they will achieve salvation?

The Answer from God’s Word:

He who is incapable of creating the world will be incapable of bringing it to an end, whereas He who created the world will surely bring it to an end, and so if one is unable to bring the age to an end and is merely able to help man cultivate his mind, then he will surely not be God, and will surely not be the Lord of mankind.
He will be incapable of doing such great work; there is only one who can carry out such work, and all that are unable to do this work are surely the enemies other than God. If they are cults, then they are incompatible with God, and if they are incompatible with God, then they are the enemies of God. All work is done by this one true God, and the entire universe is commanded by this one God.

from “Knowing the Three Stages of God’s Work Is the Path to Knowing God” in The Word Appears in the Flesh

At the end of this work, all religions will become one, all creatures will return under the dominion of the Creator, all creatures will worship the one true God, and all cults will come to nothing, never to appear again.

from “Knowing the Three Stages of God’s Work Is the Path to Knowing God” in The Word Appears in the Flesh

It is a truism that “there are no righteous upon this earth, the righteous are not in this world.” When you come before God, consider what you’re wearing, consider your every word and action, all of your thoughts and ideas, and even the dreams that you dream every day—they are all for your own sake. Is this not the true state of affairs? “Righteousness” does not mean giving alms, it does not mean loving your neighbor as yourself, and it does not mean not fighting, arguing, robbing, or stealing. Righteousness means taking God’s commission as your duty and obeying God’s orchestrations and arrangements as a heaven-sent vocation, regardless of the time or place, just like all that was done by the Lord Jesus. This is the very righteousness spoken of by God. That Lot could be called a righteous man is because he saved the two angels sent by God without care for what he gained or lost; what he did at that time can be called righteous, but he cannot be called a righteous man. It was only because Lot had seen God that he gave his two daughters in exchange for the angels. But not all of his behavior in the past represents righteousness, and thus I say that “there are no righteous upon this earth.” Even among those who are in the stream of recovery, no one can be called righteous. No matter how good your actions, no matter how you appear to glorify the name of God, not hitting and cursing others, or robbing and stealing from them, still you cannot be called righteous, for such things can be possessed by any normal person. Today, what’s key is that you do not know God. It can only be said that today you have a little normal humanity, yet you are bereft of the righteousness spoken of by God, and thus nothing that you do is proof of your knowledge of God.

from “The Wicked Must Be Punished” in The Word Appears in the Flesh

The standard by which man judges man is based on his behavior; one whose conduct is good is a righteous person, and one whose conduct is abominable is wicked. The standard by which God judges man is based on whether one’s essence obeys Him; one who obeys God is a righteous person, and one who does not obey God is an enemy and a wicked person, regardless of whether this person’s behavior is good or bad, and regardless of whether this person’s speech is correct or incorrect. Some people wish to use good deeds to obtain a good destination of the future, and some people wish to use good speech to purchase a good destination. People falsely believe that God determines man’s outcome according to his behavior or speech, and therefore many people will seek to use this to gain a temporary favor through deceit.

from “God and Man Will Enter Into Rest Together” in The Word Appears in the Flesh

There are now many people who are unable to perceive humanity’s future destination and who also do not believe the words I speak; all those who do not believe, along with those who do not practice truth, are demons! Those who seek and those who do not seek are now two different types of people, and they are two types of people with two different destinations. Those who pursue knowledge of the truth and practice the truth are the people whom God will save. Those who do not know the true way are demons and enemies; they are the descendants of the archangel and will be destroyed. Even the pious believers of a vague God—are they not also demons? People who possess good consciences but do not accept the true way are demons; their essence is one of resistance to God. Those who do not accept the true way are those who resist God, and even if these people endure many hardships, they will still be destroyed. … Anyone who does not believe in God incarnate is demonic; more so, they will be destroyed.

from “God and Man Will Enter Into Rest Together” in The Word Appears in the Flesh