Isaiah 55:6

Seek the Lord while He can be found: call upon Him while He is near. Let the ungodly man forsake his way, and the unrighteous man his thoughts, and let him return to the Lord, and He will have mercy on him, and to our God: for He is abundant in forgiving. LXX: Seek the Lord: and when you have found Him, call upon Him. And after He has drawn near to you, let the ungodly man forsake his ways and the unrighteous man his thoughts and return to the Lord: and he shall obtain mercy: for He will abundantly forgive your sins. Since, then, as we have already said before, you would not receive the everlasting covenant and the faithful mercies of David, which, when you were unwilling to take them up, the throng of the Gentiles took up, I the Prophet warn you, my own people, and solemnly charge you: while there is time, do penance. Turn to Him who now speaks to you through the Prophets, who afterward will speak in person. Seek Him while He can be found, while you are in the body, while room for repentance is given; and seek Him not by place but by faith. How God is to be sought is said more fully in another place: Think of the Lord in goodness, and seek Him in simplicity of heart: for He is found by those who do not tempt Him, and appears to those who are not unbelieving toward Him (Wis 1:1, 2). Hence we too, knowing the word spoken of sinners, Those who withdraw far from you shall perish, let us say to the Lord: Whither shall I go from your spirit, and whither shall I flee from your face? If I ascend into heaven, you are there: if I descend into hell, you are present (Ps 138 [139]:7, 8). And let us call upon Him while He is near, lest through our vices and sins He withdraw far away. For He draws near to those who draw near to Him, and joyfully runs to meet the son returning after a long time. Wherefore the holy man sings in the psalm: But for me it is good to cleave to God (Ps 72 [73]:28). And Moses alone drew near to the Lord (Exod 20). And through Jeremiah God says: I am a God who draws near, and not from afar (Jer 23:23): drawing near to those who draw near to me by faith, and withdrawing far from those who depart far from me by unbelief. Because of this it is said to believers: Draw near to God, and He will draw near to you. And lest we should think this could suffice, he at once adds: Resist the devil, and he will flee from you (Jas 4:8). Of him it had been said above: Your adversary the devil, like a lion, going about, seeks whom he may devour. Resist him, strong in faith (1 Pet 5:8, 9).

How then am I to seek for you, Lord? When I seek for you, my God, my quest is for the happy life. I will seek you that "my soul may live," for my body derives life from my soul, and my soul derives life from you.… Is not the happy life that which all desire, which indeed no one fails to desire?

And yet the prophet Isaiah testifies, that the Lord God can be found when He is sought, when he says: "Seek ye the Lord; and as soon as ye have found Him, call upon Him: and when He has drawn near to you, let the wicked man forsake his ways, and the unrighteous man his thoughts." If, then, when sought, He can be found, why is it said, "Seek ye His face evermore?" Is He perhaps to be sought even when found? For things incomprehensible must so be investigated, as that no one may think he has found nothing, when he has been able to find how incomprehensible that is which he was seeking. Why then does he so seek, if he comprehends that which he seeks to be incomprehensible, unless because he may not give over seeking so long as he makes progress in the inquiry itself into things incomprehensible, and becomes ever better and better while seeking so great a good, which is both sought in order to be found, and found in order to be sought? For it is both sought in order that it may be found more sweetly, and found in order that it may be sought more eagerly.

He says, "When you who seek have found, when you have called and have found pardon, flee the former road of ungodliness and immorality and show God your face, not your back. For he will grant you mercy and give you forgiveness of sins."

Seek the Lord. Here he enjoins upon them preparation to obtain the promise. And first, he gives the divine counsel of seeking: seek the Lord, while he may be found, before adversity or death comes: seek the lord (Ps 104[105]:4); they shall rise in the morning, and shall not find me (Prov 1:28).