It is a good question. It is very important not to use feelings as a basis. Feelings can help you (especially the feeling of guilt if you do wrong. But it is best to use objective criteria, for example:
“5 For this very reason, you must make every effort to support your faith with goodness, and goodness with knowledge, 6 and knowledge with self-control, and self-control with endurance, and endurance with godliness, 7 and godliness with mutual affection, and mutual affection with love. 8 For if these things are yours and are increasing among you, they keep you from being ineffective and unfruitful in the knowledge of our Lord Jesus Christ.” 2 Peter
One can also see if they are manifesting the fruit of the Spirit. In addition toa good examination of conscience, one can measure oneself by the standard of God’s love.
“Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, always perseveres. Love never fails.” I Cor. 13: 4-8
A wise pastor once encouraged me to use it this way:
“samuraivader is patient, samuraivader is kind. samuraivader does not envy, samuraivader does not boast, samuraivader is not proud. samuraivader does not dishonor others, samuraivader is not self-seeking, samuraivader is not easily angered, samuraivader keeps no record of wrongs. samuraivader does not delight in evil but rejoices with the truth. samuraivader always protects, always trusts, always hopes, always perseveres. samuraivader never fails.”