And He spake a parable unto them to this end, that men ought always to pray, and not to faint. – Luke 18:1

Beloved, prayer has been connected with every living spiritual experience you have ever had. Will you kindly look back to the hour when you were under the fig tree and Jesus saw you. Were you not at prayer? When you first arose to go to your Father, was not your first step a prayer? When you received the assurance of salvation, was it not in answer to prayer? When His banner over you has been love, have you not felt it sweet to pray? When you have feasted at His table, and He has revealed Himself to you as He does not to the world, have you not then been in the spirit of prayer? There has been nothing grandly great or good in your spiritual life, but…where you have wrestled with God and have prevailed.

Now, beloved, we are commanded to be constant in our instancy. Is not this right? Is there any time when we can afford to slacken prayer? Would you kindly put your finger on the map of the way, and tell me where a Christian man may leave off praying? Is it when he prospers? No, for then he needs grace to carry a full cup with a steady hand. Is it when he is in distress? Doth not nature itself teach us that in time of affliction we should especially draw near to God in prayer? When should he pray, nay, when should he not pray? Where may he pray? The answer is, he may pray everywhere, for as one has well said, a man who carries his temple about with him is always in a place where he may pray; and know ye not that your bodies are the temples of the Holy Ghost? Wherever you go you carry your temples with you, and therefore be sure that you do pray. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1480.cfm