Those feelings in themselves are not sinful. But if we respond to them with unremitting anger and hostility, they can rob us of fellowship with the Lord, His peace and joy, and abundant life. We mustn't dwell on the grief others have caused us. Painful feelings may involve a missing or abusive parent, an errant or abusive mate, an ungrateful, uncaring child, or even something wrong that we did in the past. As an example of the latter, some women I have counseled have told me of their guilt and self-accusation concerning abortions or the breakup of their marriages that have haunted them for years.
Forgiveness is a key remedy for relief from painful feelings.
Two Ways to Go Jesus gave us this teaching perhaps as much as for our sakes as for those we forgive. When I've found it hard to love someone who has hurt me, I hold that person up in my hand to the Lord and ask His help. This gives me sympathy for that person, and the love of God fills in the rest. Bitterness and anger at God and others because of past experiences cause many people misery for years. Such hurtful feelings can mar their lives and those of others close to them.