For those who will seek in truth and abandon this dogma of sin and confess, sin and confess, there is a way of certainty.
Christ taught us that we must live in all holiness, that means e.g. for marriage, that sex is kept within marriage, and even for enjoyment, that prevention of becoming pregnant is OK, but not prevention that aborts a new fetus.
If you are Christian, then there is much evidence that can be shown you aside from the fact that all created things must have causes, and all complex things must have a designer. Look at the way our brains and bodies work.
The evidence for the Exodus, for God's dealings with Israel exist.