Impressions have neither one thing nor the other to do with faith. Faith has to do with the Word of God. It is not impressions, strong or weak, which will make any difference. We have to do with the written Word and not ourselves or our impressions. Many people are willing to believe regarding those things that seem probable to them.
Faith has nothing to do with probabilities.
A great many of God's children are cast down and lament their want of Faith. And now, beloved Christian friends, you are in great need to ask yourselves whether you are in the habit of thus confiding, in your inmost soul, in what God has said, and whether you are in earnest in seeking to find whether the thing you want is in accordance with what He has said in His Word. God delights to increase the Faith of His children. Our Faith which is feeble at first, is developed and strengthened more and more by us. We ought, instead of wanting no trials before victory, no exercise for patience, to be willing to take them from God's hand as a means.