I would actually suggest a somewhat different track. Consider the logic behind Tim Keller's question "who are you sleeping with?" The more fundamental issue Keller is bringing up with that the individual is more attracted to the desire to continue in sin than they are to Christ. The doubts are not so much there because the truth is not apparent, but because our minds naturally suppress that truth to maintain our autonomy and not submit to God as our rightful ruler.
While I highly value and respect apologetics, I'm concerned dealing with these doubts primarily from that perspective is akin to wrestling an alligator in a swamp rather than on land. You're in it's turf. Our minds are not neutral ground to rationally consider both sides; then enemy enjoys a home court advantage there unfortunately.
The doubts you mentioned [1) that Christ was born of a virgin, or 2) that Christ performed miracles, or 3) that Christ rose from the dead, or 4) that he will return again.] are of course things that Christians need to come to accept. But, accepting these does not make one a Christian. Satan and the demons know these as indisputable facts, but to no benefit to them. Rather, becoming a Christian is fundamentally coming to see Jesus as our redeemer. The person of Christ revealed in the gospels is self-authenticating. John's gospel makes this particularly clear. When, with the illumination of the spirit, we see enough of the person of Christ as revealed in the gospels to believe, we recognize that the gospel accounts have to be true. We don't become persuaded of the reliability of the gospel accounts only for historical reasons and come to genuine faith. Perhaps those valid apologetic arguments for the reliability of the gospels may draw people to examine them and find Christ there. But, it is ultimately seeing that Jesus has to be who he claimed to be that saves.
Once someone comes to believe in Christ, examining who Christ had to be will help them to understand that He had to rise from the dead, that He will return as he claimed, and so forth.
So, I would suggest that you consider that the origin of the doubt is an inadequate view of Christ. (As Jack K wisely pointed out, none of us have an adequate view of Christ, or we'd be sinless.) Perhaps your friend would be willing to listen to a good sermon series on John or another gospel on their drive to work? Perhaps they may consider reading a book that really focuses on the person of Christ. Get your friend to fix their eyes there, and the rest will come into alignment.
I’d like to pick up on a couple of things you zeroed in on.
We don't become persuaded of the reliability of the gospel accounts only for historical reasons and come to genuine faith. Perhaps those valid apologetic arguments for the reliability of the gospels may draw people to examine them and find Christ there. But, it is ultimately seeing that Jesus has to be who he claimed to be that saves.
And then this:
Once someone comes to believe in Christ, examining who Christ had to be will help them to understand that He had to rise from the dead, that He will return as he claimed, and so forth.
I’ve been lately impressed by something similar to these ideas. It might be hard to believe in the Resurrection, or a sinless Jesus. I find (with you) that we must come from another direction if we are to embrace those doctrines in full assurance of faith.
Of late I’ve been increasingly impressed by the idea that if we begin with what we know by nature, yet is also revealed to us in Scripture, we might begin our reflections beginning with our sin and God’s loving goodness toward his creation. In
that context, the context of our need before a good and gracious God, the love for sinners that is displayed in penal substitution can begin to make perfect sense. Foolishness can become wisdom. In other words, the wisdom of God is on display against the backdrop of our innate knowledge of God’s goodness toward his creation and our desperate need of redemption. Once the special revelation of the cross resonates with us by the internal witness of the Spirit - the virgin birth, sinless life and all the rest become necessary preconditions for the wisdom of the cross. The point being, it’s not until we see our need will we see God’s solution, the cross. And once we are illuminated to the cross, those things that are necessary for the cross to make sense become much easier to see and believe (like the virgin birth, the two natures of Christ, etc).
All that stands in stark contrast to an Evidentialist approach that would try to build a case for the Resurrection removed from any soteriological context. Acknowledging our need in truthfulness before God is, I find, the precursor to a knowledge of the Truth.
So, for the Christian, we should keep short accounts with God. Apply the gospel to ourselves day by day, moment by moment. Given the cross, of course a Virgin was with child.
