In a real sense, especially for new Christians, it is hard for us to comprehend Calvary...

Although salvation is an event as in a second birth... the realization of what Christ did for us and who God is can not be contained in 66 books of the Bible... nor can it be totally historically understood... I argue that first century Christians no more understood someone being raised from the dead than we do today, (except for some lunitics...) but some of them, and maybe some today, have seen Jesus in the flesh as risen Lord and savior...

Our trust and faith is gained as we inch closer to the truth spiritually by prayer, worship, earthly trials, and faith comes by hearing (now most people can read so that is a form of hearing...) the word of God...

Don't give up hope so easily
May God Bless you and Keep you Amen... 

You can also look at it this way, Look at how our ancestors lived and what they had to go through for us. We don't see that any more but we believe it because our family lived it. As for the cross, that was the practice of the times (possibly still to some extent today). That was a part of their history just as covered wagons were ours. 

You can.
You can comprehend what was done at Calvary.
That can take place in two levels.
First, the earthly level. You can study up historical facts, learn the culture and context of those times, understand exactly how terrible a cross was, both in physical pain and the shame/rejection. You can go to the official site of Golgotha. You can walk the hill itself. You can meet the descendants of those very same people, and see how the zeal and tradition remains to this day.

You can comprehend it in the spiritual level. You can meet God in prayer, in worship, in those sudden moments that catch you totally by surprise. You can catch a glimpse of his holiness. And you can also feel the flood of his love. Combine both. That will give you a clearer idea of why the things on Calvary needed to take place.

You don't see them every day... here and now. Some day, millions of years later, the two of us may be sitting over a table in heaven wondering if there'll ever be a 'day' when we don't see these 'incomprehensible' things.

How can you truly believe these things? Search for them. If you trust feelings, experience them. If you trust comprehension, study them. By all means, try both.