#1 “and teaching them to obey everything…”
A disciple is a student, an apprentice. If you were to apprentice yourself to a master craftsman it would be to learn his trade. You would become like him in the way you accomplish the work. But in the case of Christ, the apprenticeship is to learn his nature and to take on his character. There is no part of his ways and instruction that should be left out. God has given us his Word to gain knowledge and wisdom, and he has given us his Spirit to empower the radical transformation of our nature and conformity to his likeness.
#2 “…I have commanded you.”
Jesus taught with the authority of God the Father. His commands are not suggestions for us to consider and to pick and choose from what we like. We lay down our lives to our Master and Savior for the purpose of dying to ourselves and living unto him (2 Cor 5:15; Gal 2:20; Luke 9:23).
#3 “And surely I am with you always,”
In Acts 2 we see the fulfillment of his promise to send the Helper, the Counselor, the Spirit of God who filled them, empowering them for life and ministry. Christians are never alone because we are always with the Holy Spirit, who lives in his people. It is fine to ask “what would Jesus do?” But the better question in our lives each moment is, “what is Jesus doing?” He continues his life and ministry through each one of us and through the Church collectively.
#4 “to the very end of the age.”
The current Church Age, begun with the ascension of Jesus into Heaven, will be the last before his return. Our orders are clear, even if in his patience he waits another 2000 years for his Church to evangelize a hurting and fallen world, he will never leave us nor forsake us (Josh 1:5).
I believe in you and you need to believe in yourself.