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.