I think as Christians we can tend to put our concern of being relatable above the power that we have as carriers of God's glory. I think it's very good and beneficial to be able to relate with unbelievers. I just think it's sad and backwards when for example, a Christian who has never gotten drunk or experimented with drugs, feels that this is a detriment to them in their effectiveness of preaching the gospel to someone. 
We know that God greatly uses the testimony of one who has dabbled in the world whethey they were a Christian and were enticed back into the world by sin, or whether a person became a Christian after a life of much sin.  As powerful as these testimonies are, I think the greatest testimony is the person who has clung to Jesus and has been steadfast in their relationship with God, staying far away from sin because nothing could compare to God's love for them. And perhaps that person who has stayed far away from sin could be naive and not understand some of the world's humour, but is this really a bad thing? We are to be dead to the world and alive to Christ (Romans 6:11). We cannot be dead to both or alive to both. If we are alive to the world, then we are dead to Christ. Perhaps being dead to world does mean some naivity, but I would rather be naive then to know sin far too well.  
We certainly don't want to be in a Christian bubble where we don't know what's happening in the world. When Paul spoke to the Athenians in Acts 17:28, we could see that he was knowledgeable about their influences, and he when he spoke to them about God he supported his statement by quoting one of their poets. It's very worthwhile to broaden our perpective and become knowledgeable about why people don't believe in God, even just by reading books by atheists and seeing where they're coming from. There is no need however, for us to have walked down the same broken roads of an unbeliever in order to bring the presence of God to them.
 At the risk of stating the obvious, I want to point out that none of us were born believers. We all once had hearts that were twisted in sin .It is only by the sheer grace of God that we can have a relationship with Him and not rot away in sin, and this realization alone gives us the perception into anyone who does not know Jesus, because no matter what avenue of sin the person has taken, it is all rooted in the same problem: a heart void of Jesus. We could all relate to people just by this but even so, I would much rather know so much more the joy of being saved and be able to relate about the new life in Christ that someone is stepping into, because I too have been transformed by Jesus, rather than know from experience about their past relationship with Satan.
Jesus never sinned, yet he spent so much time hanging out with sinners and shaking their world with the love of God. Jesus needed no past experience as a tax collector for Matthew to follow Him. Jesus had no stories of partying and addictions to share with the people who came to Him, yet He didn't need any. He had the raw love of God and the Holy enticement of entering into the kingdom of light. 
 Let's not feel that we need to get things or do things for the sole purpose of being able to relate to people. God has called us to be very different from the world.We are to stand out as His people of purity and holiness who have been transformed by a living saviour. We are a peculiar people (1 Peter 2:9)and God has given us the grace to be something the world has never seen before .
We carry a love that is far greater than any natural ability to relate to someone. I think the greatest sign and wonder in the world is love. I believe that when we surrender ourselves to God, there are no limits to how He will use us to bring His presence to people.


But thanks be to God, who always leads us in triumph in Christ, and manifests through us the sweet aroma of the knowledge of Him in every place. 2 Cor 2:14(NASB)