Could I gently suggest that this is not the way to convince others to consider Christianity. It may also be contrary to God's word
In John 12, Jesus says:
47"As for the person who hears my words but does not keep them, I do not judge him. For I did not come to judge the world, but to save it. 48There is a judge for the one who rejects me and does not accept my words; that very word which I spoke will condemn him at the last day. 49For I did not speak of my own accord, but the Father who sent me commanded me what to say and how to say it. 50I know that his command leads to eternal life. So whatever I say is just what the Father has told me to say."
and also James 4 provide more sage advice:
11Brothers, do not slander one another. Anyone who speaks against his brother or judges him speaks against the law and judges it. When you judge the law, you are not keeping it, but sitting in judgment on it. 12There is only one Lawgiver and Judge, the one who is able to save and destroy. But you—who are you to judge your neighbor?
So this is really tricky ground- we shouldn't judge, so how should we, who are convinced that Jesus provides the only way to salvation, deal with those who do not profess to be Christians?
I think one way is to urge them to examine three things:
1. the basic tenements of their faith.
2. the origin of their faith, and the actions and life style of its founder.
3. what promise their faith holds for the future; what hope does it provide for dealing with sin and life after death.
Christianity is, above all else, a religion of love, as so well demonstrated in the sinless life of Jesus Christ, and in the hope that Jesus provides for the future.
Christianity has remained unchanged for thousands of years, is consistent with all the archeological discoveries made in the Middle East, and provides a clear road map to Heaven. Others may have their own answer, but as for me, I know what I've got, don't know what I'd get if I changed, and therefore will stay with the Lord forever.