Gardiner Spring (1785-1873) wrote a valuable treatise in 1813 titled Essays on the Distinguishing Traits of Christian Character that has stood the test of time (it was republished by Northampton Press in 2010).
In this collection of essays, Spring examines in the light of God's Word certain crucial aspects of the life of a Christian: conviction of sin, repentance, assurance, love to God and the brethren, faith, humility, self-denial, non-conformity to the world, practical obedience, growth in grace, and prayer. These fruits of the Spirit are indeed the distinguishing characteristics of Christians in a world which runs in the opposite direction, and they are to be sought after and cultivated in every Christian's life.
May this little book be a blessing and an encouragement to your Christian walk.