We all feel like a left shoe or a third wheel sometimes.
But consider Paul's words in I Corinthians 12 (from NRSV though I usually read KJV). We are all an important part of the church, and if we're missing on Sunday or other days when the body of Christ gathers, the whole feels it. You are needed. You are wanted.
Here's how Paul puts it:
12 For just as the body is one and has many members, and all the members of the body, though many, are one body, so it is with Christ.
13 For in the one Spirit we were all baptized into one body — Jews or Greeks, slaves or free — and we were all made to drink of one Spirit.
14 Indeed, the body does not consist of one member but of many.
15 If the foot would say, "Because I am not a hand, I do not belong to the body," that would not make it any less a part of the body.
16 And if the ear would say, "Because I am not an eye, I do not belong to the body," that would not make it any less a part of the body.
17 If the whole body were an eye, where would the hearing be? If the whole body were hearing, where would the sense of smell be?
18 But as it is, God arranged the members in the body, each one of them, as he chose.
19 If all were a single member, where would the body be?
20 As it is, there are many members, yet one body.
21 The eye cannot say to the hand, "I have no need of you," nor again the head to the feet, "I have no need of you."
22 On the contrary, the members of the body that seem to be weaker are indispensable,
23 and those members of the body that we think less honorable we clothe with greater honor, and our less respectable members are treated with greater respect; 24 whereas our more respectable members do not need this. But God has so arranged the body, giving the greater honor to the inferior member,
25 that there may be no dissension within the body, but the members may have the same care for one another.
26 If one member suffers, all suffer together with it; if one member is honored, all rejoice together with it.
27 Now you are the body of Christ and individually members of it.