My belief system is rigid because it is founded in the words of Scripture. We are not having a denominational discussion here. If someone wants to talk about Baptism or eschatology or something like that, I'm all for it. and I'll listen to anybody's different view points with a willingness to be proven wrong because, at the end of the day, though I disagree with my Presbyterian brothers, for example, on small points of doctrine, we are still brothers who believe in the same God, serve the same Christ, and preach the same gospel.
But these aren't the conversations that we are having here. We are having the conversation about whether or not Christ is Lord, and the only way to heaven, which is what He Himself taught and said that anyone who does not believe is condemned. That is a matter of eternal life or death that we are talking about in here, so of course I'm rigid. This isn't doctrinal disagreements, but the orthodoxy and heresy. There is no other way to be than rigid, or I wouldn't even be a Christian. That is just a strange premise to expect a Christian to not be rigid about the very thing that makes Him a Christian.
But further, it isn't my responsibility to reach people. My responsibility is to proclaim the truth. I trust the Holy Spirit with the rest. Like Jesus on the shore of the sea of Galilee, Peter threw his net into the water, but it was Christ who brought the fish. All I can do is throw the net out. I trust Him with the rest.