Ek Onkaar Sat Naam
There is usually no problem at all with the original, root, theology. Any problems that do arise (with respect to tolerance) are generally through a combination of lack of understanding of the religion claimed to be followed by current claimants, and efforts by the mind to self-satisfy.
Mortals are presented with mountains to climb if they are expected to break free from these bonds, and suddenly become virtuous in every respect. They have so much working agains them, ranging from inter-alia ignorant preachers, misinterpreted scriptures, peer pressure, media pressure, economic pressure, political pressure, family pressure. These are all affecting their thinking all the time, to the point that they are deeply attached. Any attempt to live outside of society's "norms" are often seen as "insane" moves, or counter society. Some people are branded as revolutionaries, some terrrorists, some fanatics, some villainous, some just so weird that they deserve intense scrutiny and quarantining from rest of society (like gays).
They are bullied by society as a whole, and humiliated. The ego of these affected people suffers severe setbacks. The rejected people seek support. They attempt to group and attempt to carry on against the onslaught. Some manage to do it, and hence we have wars between peoples with different outlooks on life. Some of those who can't attach to any society that shares their point of view, either continue in intense suffering, simply commit suicide, or commit suicide taking out other people with them, that they perceive as enemies that lead them to their fragile frame of mind.
Solution: Follow Sikhi with a purpose. Listen, contemplate, meditate, understand and practice detachment. Think before reacting. Try to change one's mindset from one who is ensnared by 5 evils, to that of one who is is detached. Do this before one hits any obstacle, such as social bullying, humiliation and persecution. Past Sikhs did and current sikhs can do it. However it is hard to beat worldy forces, but knowing that it means one must do more than passively relying on God's grace. Make one's effort as part of the Lord's Hukam.
When one is detached, then there will be no ego to take any hit. 
There are also other religions that can assist with attaining the same detached frame of mind, if one does not understand Gurbani or does not know how to practice aspects of Sikhi that can lead to loss of self-identity.
Sat Sri Akal
