Assalaamu Alikum Wa Rahmatullahi wa Barakaatuh
When we are talking about being kind and gentle then that means in treating others and in the way of giving the Elm and Naseeha humbly...
For Allah`s commandments and rules of the Deen; then there is nothing called harshness...This Deen is the religion of Rahmah (Mercy) then how come we call it harsh in its rules, commandments and teachings ...no way to be when its the perfect merciful way That The Most Merciful The Most Compassionate made for us and honored us to carry its name and be His slaves and servants...
gentleness, kindness, warmth, excellent manners , mercy, wisdom and all good manners were the khuluq of Rassol Allah (peace and blessings of Allah be upon him) and all are must be in treating of people and also to be understanding for the differencies in personalities, madhabs and condtions of the others...
Allah`s rules and limits are The rules and limits no matter what or whether others liked it or not; then you don`t have the right to choose or to object or to open your mouth with one word cause those are from The All Knower and you have nothing from the unseen or the unknown knowledge but Allah and He Is The Only One Who knows what best for us and we are not talking about those here but the best way of making the others accept those rulings and commandments peacfully and freely and also be pleased and have peace with them.
this is it, Allah says:"So by mercy from Allah, [O Muhammad], you were lenient with them. And if you had been rude [in speech] and harsh in heart, they would have disbanded from about you. So pardon them and ask forgiveness for them and consult them in the matter. And when you have decided, then rely upon Allah. Indeed, Allah loves those who rely [upon Him]. (
159)" Surat Aal Im`raan
The kindness, mercy and patience are great and important tools to make Da`wa, to advice to make others love the deen of course with the proper knowledge in shaa Allah...
and at the end Allah says:"Say, "Obey Allah and obey the Messenger; but if you turn away - then upon him is only that [duty] with which he has been charged, and upon you is that with which you have been charged. And if you obey him, you will be [rightly] guided. And there is not upon the Messenger except the [responsibility for] clear notification." (
54)" Surat Annoor
So, our job here is to only convey the message and explain it in the best way and there is no best way like what Allah taught our beloved Muhammad (peace and blessings of Allah be upon him) and whether others accepted it or not then the hidayah is not in our hands but in Allah`s and Alhamdulilah we have conveyed the message, did our part from giving the naseeha and informing others and in shaa Allah we are innocet and free from that before Allah in the Day of Judgement...
Allah says:"Not upon you, [O Muhammad], is [responsibility for] their guidance, but Allah guides whom He wills." Surat Al Baqarah
and:"Show forgiveness, enjoin what is good, and turn away from the foolish (i.e. don't punish them). (
199)" Surat Al Aaraaf
and says:"Indeed, [O Muhammad], you do not guide whom you like, but Allah guides whom He wills. And He is most knowing of the [rightly] guided. (
56)" Surat Al Qasas
May Allah guide us all , give us Sabir, Hikmah , Knowldge , humblness and help us to worship Him right and to love for each other the eternal living in the highest level of the Paradise and even without any reckoning Ameeeeeeeeeeen