How can we best promote the Gospel among the unconverted?

How do Christians bear faithful witness to Christ among the unconverted? How recommend our faith in God and open a door for the promotion of the Gospel?
1 Every sphere is most suitable for Christians to commend the Christian faith: private and public, whether husbands, wives, servants, or masters; 'walking' as Christians in all conversation, conduct and course of life.

2 This walk is conducted in wisdom: by,
1)'redeeming the time';
2) 'suavity of speech' (John Calvin);
3) prayer.

3 The Christian is ever mindful of this obligation because of its objective: 'to those that are without';
because 1) we are absolutely convinced of the perilous state of sinners;
2) we are absolutely convinced of the only remedy for that state;
3) we are absolutely convinced that our walk will have results upon those that are without. Therefore the Christian's walk is always purposeful, deliberate, thoughtful.

Application.
1 Three things Christians must avoid: diminishing the Gospel by public quarrels amongst themselves before the ungodly; diminishing the Gospel by tolerating anything that undermines it; diminishing the Gospel by pretending that no changes are required by becoming a Christian.
2 Three things Christians must remember about this walk: it is of a higher standard than nature; it is answerable to and agreeable with the glorious truths the Gospel speaks of; it commends the beauty, excellency and glory of the Gospel.
3 A solemn obligation:- to live so as to commend the Christian faith to those that are without.