How do we know that prayers offered in faith are effective?

The effects of prayer are closely linked to faith, as noted in James 5:16, which states, 'the effectual fervent prayer of a righteous man availeth much.' This underscores the importance of both sincerity and faith in our petitions to God. The example of Elijah illustrates this point; through prayer, he was able to bring about a drought and later restore rain (1 Kings 17:1, 18:1). The assurance we have is that prayers grounded in faith are not in vain and will indeed reach God’s ears, resulting in His action according to His will.