Paul's idea of imitation is a repudiation of Jesus' radical ideas of eschatological repentance, which involved flight from traditional social conventions in order to escape the imminently coming judgment. In point of fact Jesus' idea left nothing positive to imitate. This is why Schweitzer could speak of Jesus' ethic as a negation of ethics.
Paul's "way" on the other hand was a rationalization of those conventions after the failure of the eschaton and the impending failure of the parousia. Instead of rejecting traditional social roles he simply accepted them and invested them with new meaning.
For though you have countless guides in Christ, you do not have many fathers. For I became your father in Christ Jesus through the gospel. I urge you, then, be imitators of me. Therefore I sent to you Timothy, my beloved and faithful child in the Lord, to remind you of my ways in Christ, as I teach them everywhere in every church.
-- I Corinthians 4:15ff. (RSV)
And you became imitators of us and of the Lord, for you received the word in much affliction, with joy inspired by the Holy Spirit;
-- I Thessalonians 1:6 (RSV)
As ye know how we exhorted and comforted and charged every one of you, as a father doth his children,
-- I Thessalonians 2:11
Paul is, in fact, all over the map on this, spilling a lot of ink on the patriarchs Abraham, Isaac and Jacob as fathers even though he knows we have but one father, God. He seems completely ignorant of the teaching of Jesus, which rejected all human fathers in favor of the fatherhood of God. Paul notably also does not use the language of "following" as found in the gospels ("come after me", "follow me"). Instead he speaks of mimesis, which in its turn is foreign to the gospels.
Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all,
-- Romans 4:16
And not only this; but when Rebecca also had conceived by one, even by our father Isaac;
-- Romans 9:10
As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers' sakes.
-- Romans 11:28
... all our fathers were under the cloud ...
-- I Corinthians 10:1
But ye know the proof of him [Timothy], that, as a son with the father, he hath served with me in the gospel.
-- Philippians 2:22
The whole thing degenerates into the familial as the pressure of the delay of the parousia re-invigorates traditional human social roles:
Unto Timothy, my own son in the faith: Grace, mercy, and peace, from God our Father and Jesus Christ our Lord.
-- I Timothy 1:2
Rebuke not an elder, but intreat him as a father; and the younger men as brethren;
-- I Timothy 5:1
To Timothy, my dearly beloved son: Grace, mercy, and peace, from God the Father and Christ Jesus our Lord.
-- II Timothy 1:2
To Titus, mine own son after the common faith: Grace, mercy, and peace, from God the Father and the Lord Jesus Christ our Saviour.
-- Titus 1:4
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And call no man your father upon the earth: for one is your Father, which is in heaven.
-- Matthew 23:9
