No you don't. As I've explained to you there are 2 types of people who deny God and call themselves atheist, and you don't know which one is which.I know who and what they are.
Our God and savior Jesus came into the world with love, and understanding what it's like to be human. Without love and understanding your preaching is useless.
And without answering people's questions about the Bible and Christian community, your preaching would be of very little effect. The saved will eventually be saved, but their time as lost in the world will cause enormous amount of sin, and it's our job to prevent it by preaching with love, understanding and doing what we can to help people stop sinning.
As opposed to what? Dismissing them as lost? You think that's loving them?Spending years testifying to them, is not not loving them.
You wouldn't need to spend more time testifying if you actually knew the Bible you were preaching and could answer people's objections.