Tolerance is being ok with something/someone different from you, It doesn't necessarily involve committing something wrong like forgiveness.

forgiveness is if someone has offendet you. and instead of being upset you get over it and start over it and change your negative feelings. tolerance is about having an objective and fair attitude towards the mindset of someone else (e.g. about religion, nationality, opinions, rites, preferrences) even if it is different to your own opinion on that topic.