A brief answer for how Paul’s eschatology informs his exhortations within the Pastoral Letters.
For Paul, the Kingdom of God was an already not yet reality made possible through the work of Jesus Christ. God, through the Gospel had already provided salvation from the penalty of sin, was continuing to save Christians from the power of sin, and would upon Christ return, save Christians from the presence of sin (Vandersteldt, Kindle Location 782). When it comes to Paul’s eschatology the resurrection of Christ is central, for it provides the hope and the motivation for living a life of faith in the Gospel (DPHL, 265). A proper understanding of this Gospel and the person and work of Christ is crucial for salvation and proper worship of the God who delivers men from bondage to improper worship and sin’s curse.
The Gospel of Christ and its implications for living must be believed, proclaimed, held to, and defended from any perversion that threatened to destroy it or dilute it. An erroneous view of the Gospel, Christ, or His return would inevitably lead to confusion and perhaps sinful behavior. This was the case in the Thessalonian church who misunderstood the imminent return of Christ, leading some to a misguided understanding about work (DPHL, 266; 1 Thess. 5:12-14).
Paul commanded church leaders such as Timothy to teach sound doctrine and defend the faith (2 Tim. 2:15; 4:2; Titus 1:9). Exhortations for this and for cooperation in the sanctifying work of the Spirit flow from Paul’s eschatological understanding of the Christ event in God’s salvific history, the identity that Christians now have as being in Christ, and the future hope that Christians have in the resurrection and Christ’s return (DPHL, 665). False teachers were to be refuted and the Gospel continually proclaimed as motivation to obey—not just its past or present implications, but the future implications for those believing in the Gospel.
“Eschatology”, Dictionary of Paul and His Letters. Downers Grove, IL; Nottingham, England: IVP Academic; Inter-Varsity Press, 2009. Accordance Bible Software Version. 253-269.
“Pastoral Letters”, Dictionary of Paul and His Letters. Downers Grove, IL; Nottingham, England: IVP Academic; Inter-Varsity Press, 2009. Accordance Bible Software Version. 658-666.
Vanderstelt, Jeff. Gospel Fluency: Speaking the Truths of Jesus into the Everyday Stuff of Life. Wheaton, IL: Crossway, 2017. Kindle Edition.