Evangelism is not only winning someone to Jesus by the grace of God in the preaching of the gospel. It is also winning them to the church by that same grace and gospel. The local church is increasingly being thought of as optional by professing believers. In fact when I say something like, "You can't do all that Christ calls you to do apart from the local church" I often get pushback online.
But read the words of the Apostles John.
That which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life—the life was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us—that which we have seen and heard we proclaim also to you, so that you too may have fellowship with us; and indeed our fellowship is with the Father and with his Son Jesus Christ.
(1 John 1:1-4, ESV)
Do you see it? John says we preach the gospel so others would have fellowship with us, and our fellowship is with the Father and his Son Jesus Christ. The Apostles preached the gospel not only to bring people individually to Jesus, but also collectively into his family gathered into local churches. I wonder how many of us would be comfortable saying what John says here. "I'm telling you about Jesus because I want you to be with us, and we are with Jesus." It sort of sounds like we believe our church is important. That to have know Jesus means you need to know his people. It sounds that way because it's true.
Of course it's possible to be converted and not be a part of the local church. Possible. And dangerous. You see, the goal–the mission of the church–is not to see converts, but to make disciples. Conversion is but a part of that process. The making of spiritually mature disciples who obey Jesus Christ can only fully happen inside the church. It is in the church where we discover and exercise our spiritual gifts; where we bear one another's burdens, exhort, encourage, and rebuke one another; where we share in one body, one Spirit, one Lord, one faith, one baptism, one Father.
Preach the gospel. Preach the hope of Jesus' life, death, and resurrection for sinners. Preach it with the aim of reconciling people to God and receiving them into the fellowship. The local church (in all it's ministries and meetings) is "where it's at," not because it's cool, entertaining, or perfect, but because that it is where Christ stands with his people, fellowshipping with them, and leading them through this life into the life to come.