Can doubt be good? U bet! How so? When doubt leads to questions, and the questions lead to answers, that help our understanding, then doubt is good. When doubt and its uncertainties lead me to trust, whether there is proof or not, then doubt is good. Also, when my trusting leads to hope, then the process of doubting has done well.
In John 20:24-31, Thomas doubted that Christ had risen until he was able to witness it with his own eyes and touch The Risen Lord with his own hands. Jesus calls those who believe without seeing, blessed! Doubt that refuses to believe even when answers are presented causes us to lose faith. This is when doubt is not good.
Let any doubt in your life today; deepen your faith as you continue to search for answers. Don’t let doubting be a constant state. In the bible, Christ appeared to doubting Thomas one week after He appeared to the other disciples. Therefore, a good rule of thumb might be to limit our doubting to one week of seeking for answers. You have to put some effort into seeking answers to your questions. I pray that when you receive the answers that you accept the answers so that doubt does not destroy your faith.