This is another quote from Metropolitan Isaiah of Denver, on Oct 1998.
"Whether we stand or kneel at the Epiklesis on Sundays, we should do so with sincerity of heart and humility. It should never be as an outward show of piety (kneeling) or of our Orthodoxy (standing). This is audacity.
In comparing the act of kneeling with the consumption of food during periods of fasting and abstinence because both have to do with self-discipline, Saint Paul tells us, "But food does not commend us to God, for neither if we eat are we the better, nor if we do not eat are we the worse. (1 Corinthians 8:

Elsewhere Saint Paul is even more emphatic. He says, "Receive one who is weak in the faith, but not to disputes over doubtful things. For one believes he may eat all things, but he who is weak eats only vegetables. Let not him who eats despise him who does not eat, and let not him who does not eat judge him who eats; for God has received him. (Romans 14:1-3)
Parallel to the discipline regarding food consumption, we can correctly say that the kneeling or the not kneeling by the faithful in the Sunday Divine Liturgy must never become contentious among the faithful. If one kneels at the Epiklesis it must not be out of repentance, but out of awesome joyfulness and fervent love that the Holy Spirit comes upon us. If another stands during the same time, he should not do so like an Orthodox spectator in judgment of the kneeling sinners, but must always stand with bowed neck and head and eyes closed or lowered, rejoicing in God's love through the descent of the Holy Spirit Who comes to sanctify all who are in a prayerful stance in the house of God and especially to change the bread and the wine into the sanctifying Body and Blood of the Lord.
Orthodoxy is not legalistic; it is pastoral."
By the way I stand and my wife kneels.