The saying of the corporate amen is a great covenant privilege, and has the force of a binding oath. We never want to take it lightly, or invoke it to no purpose, or, worst of all, to mumble it.
As we sing the psalms, we offer back to God what He gave us to sing to Him. When we say amen at the conclusion of each psalm or him, we are owning what we have said. We are committing ourselves to what was just sung. In the seventeenth century, there was a controversy in which some maintained that for everyone to sing the same words at the same time was a “set form of worship” and would stifle all true religion. This is, of course, a foolish thing to maintain, but when you mumble an amen you are created a circumstance where such a belief can be justified.
We say amen when the Scriptures are read to us. This indicates that we have heard God speaking. We have paid attention. We have listened, and we acknowledge that His Word is good, all of it. Say amen as though you have just heard your very life spoken aloud—for you have.
We say amen after each of our petitions has been offered up to God. We do so because we are praying as a congregation, seeking to grow in likemindedness and loving empathy. In the amen, we suffer with those who are sick, rejoice with those who rejoice, and we beseech the kindness of God with those who have a heart full of supplication. This is what it means to be the body of Christ.
All gardens in this fallen world must be tended, or they will fill with weeds. The fact that we have rejected spontaneous worship, and we have, is no reason for us to believe that liturgical worship cannot fill up with the noxious weeds of presumption, self-righteousness, snobbery, and other forms of spiritual thistles and morning glory. We are protected by no external forms out there. All the blessings of the covenant are received by faith, including the blessing of covenant faithfulness. Do you believe this? Then as every chance is given, it should delight you to say amen.