1. If those questions "Have you ever (at any time in your life) ever ..." are asked to a Christian, problems will surface by implication. Since a Christian is a new creation, who has had his spiritual identity changed at the point of salvation/forgiveness, God NO LONGER views him as being in his past forgiven sins—liar, thief, adulterer, murderer, etc. We know this because the dying thief, who repented and got saved on the cross, was going to enter Paradise. God no longer viewed him as a thief, because thieves will not inherit the kingdom of God (1 Cor. 6:9,10). 1 Cor. 6:11 is most clear on this too:
And that is what some of you were. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God. (1 Cor 6:11)
The Corinthians, who were of the some mentioned in verse 11, were formerly those past wicked things cited in verses 9,10, but not at that present time because they were washed, sanctified, justified and walking holy.
Ray Comfort's question: Have you ever stolen anything, does NOT make a Christian a thief, because he has been forgiven. Hence, Ray Comfort's approach is flawed and misleading, though it is popular and often used. Again, a Christian is no longer a thief because he was forgiven, just like an alcoholic who gets saved (and set free from that slavery to drink) is no longer a drunkard!
2. The real salvation issue is NOT: if one has ever lied, stolen, lusted, hated, etc., as Comfort suggests with his questions. The real salvation issue is: Are you NOW in those sins (lying, theft, hatred, lust, etc.)? It is one's PRESENT BEHAVIOR that reveals a present salvation or the lack of it (1 John 3:10; etc.). Since a Christian can backslide and die spiritually, as King David did, that possibility must be considered to accurately discuss salvation. Since Ray Comfort wrongly doesn't believe a Christian can die spiritually, he can not consider that possibility. All who believe in once saved always saved, including Ray Comfort, will always have a distorted view of salvation, grace, sin, the gospel, etc.
People who correctly reject and oppose eternal security should never use Ray Comfort's flawed approach, his tracts, link to his ministry, endorse his teachings or support that message in any way. To do so is to spread some form of deception. His questions are never shown in the book of Acts as a way the early disciples evangelized. Moreover, those questions originated from his once saved always saved darkened view!
GOD BLESS YOU.