It's not just new Christians that can struggle with worship. At my church, if the choir isn't present then there's a distinct lack of enthusiasm from the congregation when it comes to vocalising worship through singing hymns. I think this is partly due to many people being afraid of what their singing will sound like without the trained and talented voices of the choir to shield them and encourage them to lose our inhibitions. (Either that, or a stifling unfamiliarity with the melodies of some hymns). But there's a big problem with this. By concerning ourselves with what other people may or may not think when we fail to hit the high notes during Gloria in excelsis Deo, we turn the focus of our worship away from God and onto ourselves.
Worship is about God. It's not about us. It provides us with a way to thank and praise God, but it also works to remind us of who God is, his power, his glory. The worship at my church is pretty tame in comparison to some of the "trendier" Anglican churches, and the first few times I experienced a more visibly and audibly lively form of worship (hands in the air, dancing, worship bands) I was definitely guilty of becoming self-aware about how I worshipped God. One verse which helps to remind me how I should approach worship is Colossians 3:2: "Set your minds on things above, not on earthly things."
We restrict ourselves from worshipping in spirit and in truth when we hold back. Jesus said: "Yet a time is coming and has now come when the true worshippers will worship the Father in the Spirit and in the truth, for they are the kind of worshippers the Father seeks," (John 4:23). If we are concentrating on how we appear or sound during worship, whether this means trying to sing louder than everyone else or not singing at all, then we are preventing ourselves from worshipping in the Spirit and in the truth because we are not being honest about focusing entirely on God. When it comes to worship we need to forget about everyone else. It's not a competition. If we feel that we're becoming easily distracted, then closing our eyes as many of us do during prayer can help us to focus on God and forget about what's going on around us. We shouldn't be forced into worshipping in a certain way but just as we open our hearts to the Lord, we can also open our arms to him too.
