At some point you just have to cross the line.
Maybe you're not comfortable talking to someone you don't know. Maybe you're not comfortable introducing a meaningful topic into a casual conversation. Maybe you love to talk deeply with people but have never ventured into a spiritual conversation.
If you want to share the Gospel with people that are far from God, you're going to need to cross the line.
Me? I hate the fact that EVERYONE is looking at their phone, usually with earbuds in. The only way to start a conversation with them is to cross the line of interrupting them. (Don't worry, most of us just waste time on our phones anyway.)
In any of these scenarios the line is there. It needs to be crossed. The mission of Jesus calls us to leave our comfort behind and reach out to others.
Finally, wherever your line is: It's not going to be any easier to cross it tomorrow. You might as well go ahead and do it today.