Jesus encouraged persistent prayer when he told the Parable of the Persistent Widow. While the unjust judge gave justice to the widow only because of her persistent appeals, God our Father is eager to answer our prayers in the ways best for us.
However, persistence in prayer on our part is called for, just as Moses prayed for the Israelites throughout their battle with the Amalekites, even when he needed help. Timothy, too, is urged to persistence in his ministry, whether it’s convenient or not. For our persistence in prayer is not to change God’s mind but to change us to conform to God’s nature.