Jeremiah 17:8 English Standard Version (ESV)

He is like a tree planted by water,
    that sends out its roots by the stream,
and does not fear when heat comes,
    for its leaves remain green,
and is not anxious in the year of drought,
    for it does not cease to bear fruit.

I begin with this passage to demonstrate how a man who has spiritual fruit reacts to adverse conditions.

Galatians 5:22-23 (ESV) But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law.

These are the fruits of the spirit, fruit produced by the spirit. Which of these attributes cannot be reproduced by self-effort? Good men with good intentions will produce these fruits in the flesh. They will mask self-righteousness in false humility.

An old teaching comes to mind that says a tree produces fruit by nature not by effort.

Matthew 7:20 (ESV) Thus you will recognize them by their fruits.

This is not an encouragement to become fruit inspectors. We are not to judge others nor ourselves in these matters. If your roots extend into the steam and the Holy Spirit brings life to you, you need not worry about what fruit is being produced. If you are not rooted and grounded no amount of effort will produce fruit during a drought.

Matthew 6:27 (KJV) Which of you by taking thought can add one cubit unto his stature?

Once cubit is equal to one step indicating both length of life and forward progress. Our human insecurities seek reassurance in signs and wonders. What can I measure to ensure I am making forward progress? That is a worldly attitude and not a kingdom attribute. If we trust God we will not worry about those things which are not within our control. Fruits of the spirit are produced by the spirit and not within our control. Trust God to finish what He has begun. Be not anxious.