Some of us are called to witness by leading holy lives and acting in a way so as to not defame the name of Christ. Some have the gift of evangelism and are called to go out and preach the gospel. There are many other gifts as well.
1Co 12:4 Now there are varieties of gifts, but the same Spirit;
1Co 12:5 and there are varieties of service, but the same Lord;
1Co 12:6 and there are varieties of activities, but it is the same God who empowers them all in everyone.
1Co 12:7 To each is given the manifestation of the Spirit for the common good.
1Co 12:8 For to one is given through the Spirit the utterance of wisdom, and to another the utterance of knowledge according to the same Spirit,
1Co 12:9 to another faith by the same Spirit, to another gifts of healing by the one Spirit,
1Co 12:10 to another the working of miracles, to another prophecy, to another the ability to distinguish between spirits, to another various kinds of tongues, to another the interpretation of tongues.
1Co 12:11 All these are empowered by one and the same Spirit, who apportions to each one individually as he wills.
1Co 12:27 Now you are the body of Christ and individually members of it.
1Co 12:28 And God has appointed in the church first apostles, second prophets, third teachers, then miracles, then gifts of healing, helping, administrating, and various kinds of tongues.
1Co 12:29 Are all apostles? Are all prophets? Are all teachers? Do all work miracles?
1Co 12:30 Do all possess gifts of healing? Do all speak with tongues? Do all interpret?
1Co 12:31 But earnestly desire the higher gifts. And I will show you a still more excellent way.
To say that we must all evangelize is not biblical. Some do not have that gift.
We do have an obligation to know our faith and be able to defend it.