Muslims have a message to spread Islam in the most peaceful way.
A resistance came at that time from the non believers, and they did not want Islam to spread and they started fighting and killing Muslims, and because Muslims were so keen to take the instruction from the Holy Quran, the verses of killing those non believers had came at that time.
Those verses were applied at that time.
please understand the History of Islam, if you do not read then your judgement will be wrong, Islam tells us to seek for the truth.
Up to this moment I have a conclusion that your information about Islam is very limitted.