It is certainly striking that these expressions of passionate desire to come into living fellowship with God are found in the Old Testament rather than in the New. Is it not possible that we, because we have the privilege of approaching God at all times without restrictions, are sometimes in danger of underestimating its value or even neglecting its exercise? Must not a David put us to shame when he cries in Psalm 63: 'O God, thou art my God, earnestly will I seek thee: my soul thirsts for thee, my flesh longeth for thee in a dry and weary land where no water is. Because thy loving-kindness is better than life my lips shall praise thee'? If he longed like this for the less, how much more earnestly ought we to cultivate the greater?
Geerhardus Vos, Grace and Glory, p.173f