From "Prayer, Faith, and Healing," reprinted with permission of the publisher, Rodale, Inc.

It's in the Lord's Prayer. It's in the Sermon on the Mount.

We must love our enemies. We must pray for those who have hurt us. We must forgive those about whom we are embittered.

Why? Jesus said so. Why else? Here's a "selfish" reason. It's for our own good. We must be willing to love unconditionally, which is what forgiveness is, if we want to experience the blessings of God's love, says Vernon M. Sylvest, M.D., a physician with a prayer-based, holistic medical practice in Richmond, Virginia, and author of "The Formula: Who Gets Sick, Who Gets Well." If we want God to answer our prayers, then we must forgive those we feel have harmed us and we must ask God to bless them. It's the rule.

The Gospel of St. Mark quotes Jesus on this: "And whenever you stand praying, if you have anything against anyone, forgive him, that your Father in Heaven may also forgive you your trespasses. But if you do not forgive, neither will your Father in Heaven forgive your trespasses." (Mark 11:25-26 NKJV)

Before we can expect our prayers to be answered, we need to develop and maintain forgiving hearts, letting go of grudges, bitterness, hatred, or a desire for revenge and retaliation, says the Rev. Siang-Yang Tan, Ph.D., professor of psychology in the graduate school of psychology at Fuller Theological Seminary in Pasadena, Calif., and senior pastor of First Evangelical Church in Glendale, Calif. What we hold against someone else will hurt us, hinder us, and stymie our prayer efforts.

Here's another good reason to forgive: If we are unwilling to let go of our anger toward another or ourselves, it becomes our block to God's love; thus we do not witness prayers answered, says Dr. Sylvest.

This sentiment is echoed by Catholic Scripture scholar Marilyn Gustin in her treatise, "What the Bible says about Forgiveness." She writes: "The capacity to love and receive love and the capacity to forgive and receive forgiveness are intimately bound to each other. Who could say which comes first in all the complexities of a human life. It is vital to see that both capacities move circularly."

So pray for forgiveness. Ask God to forgive us for any ill or vengeful thoughts, and ask God to help us learn to forgive others, recommends Dr. Sylvest.

This is not some new or controversial faith teaching. Some ancient wisdom on this comes from the monks of the first few centuries, known as the Desert Fathers. For instance, Abbot Zeno said, "If a man wants God to hear his prayer quickly, then before he prays for anything else, even his own soul, when he stands and stretches out his hands toward God, he must pray with all his heart for his enemies. Through this action God will hear everything that he asks."

When should we forgive those who have hurt us? When should we pray for our enemies? Jesus is pretty clear on this. He says that we should do it anytime we pray.

How to Forgive
It's not enough to just say, "I forgive you," says Dr. Sylvest.

It's important to understand what forgiveness is and what it is not, he says. Forgiveness is not saying, "Although you are a miserable person who does terrible things, I forgive you because I am spiritually mature and evolved." Or, "I'm a terrible, miserable person, too, who also does miserable things, so of course I forgive you." And forgiveness doesn't have "ifs" or "buts" attached, such as, "I'll forgive you if you change" or "I'll forgive, but I'll never forget." Forgiveness, he says, like the love that makes it possible, is unconditional.

True forgiveness is willingness to let go of judgments and see the situation differently. It has to do with experiencing love and joy instead of fear and hate, says Dr. Sylvest.

How do we do this? We need to surrender old perceptions and open ourselves to new ones that reflect the love of God--releasing fear, guilt, unresolved grief, and anger, and letting it be replaced by love and joy.

 We can't change our feelings, but God can, says Dr. Sylvest. We should acknowledge in prayer that we are angry at a person or that we feel guilty, but that we are willing to not have those feelings. We need to acknowledge that we're willing to see the situation differently and feel love for that person and ourselves. Then we need to open our minds and allow God to work on us; allow God to show us how to love that person; allow God to create a new perspective. He always will if we ask.

We may choke on those words and have to say them over and over in prayer after prayer until we really feel them. But that is our job, says Dr. Sylvest. We should pray it through until it happens, he advises.