Those words are the words of Jesus, but we cannot apply them broadly to those who do not believe as we do. There are indeed those who may be malicious, but many are honest dissenters and we shouldn’t regard them uncharitably or judgementally.
We cannot be sure that this sub-form will not in time be a means to draw souls to the fullness of the truth.
Any lack of charity has no chance of doing so. People most often have honest beliefs, whatever they are, and we trust God to work through His grace and our respectful charity and grace.
Before His ascension, Jesus said, “All authority in heaven and on earth has been given to me. Go therefore, make disciples of all the nations; baptise them in the name of the Father and of the Son and of the Holy Spirit, and teach them to observe all the commands I gave you. And know that I am with you always, yes even to the end of time.” [Matthew 28:17-20]
That is, Jesus does not just send us to believers, to to witness to unbelievers.
“You will receive power when the Holy Spirit comes on you, and then you will be my witnesses not only in Jerusalem but indeed…to the ends of the earth.” [John 16:15]
"Think of a farmer, how patiently he waits for the precious fruit of the ground until it has the autumn rains and the spring rains. [James 5:7]
God bless you.