From Alister E. McGrath’s Mere Apologetics: How To Help Seekers & Skeptics Find Faith:

Evangelism is different. It issues a personal invitation: ‘You are invited to the feast! Please come!’ Apologetics lays the ground for this invitation; evangelism extends it. Apologetics establishes and proclaims the plausibility and desirability of the gospel; evangelism summons people to enter into it and share in its benefits.