Sinclair Ferguson, while giving a lecture about John Owen on the Holy Spirit, explained that the trials through which the Christian goes are actually evidence of the sealing of the Spirit. Ferguson says:
Contrary to the kind of thing that was said in his day and in ours–that if we only had more of the Spirit then all the tensions and difficulties would begin to disappear from our lives–Owen argues that the really foundational and fundamental tensions and trials in the Christian life are not those that will be removed by the Spirit, but those that are actually caused because the Spirit is present with us. Its because the Spirit dwells in us that the flesh lusts against the Spirit, and the Spirit wars against the flesh. But just because, as the earnest of our inheritance, He dwells in us and therefore sets up the tension that is characteristic exclusively of the Christian believer, He is also thew Comforter, because He is the earnest of the inheritance. And the very struggles and trials through which the Christian goes as a Christian believer therefore for Owen are paradoxically also his comforts because they are the fruit of One who is in him, to assure him of the fullness of the inheritance that is to be his in the last day.
You can listen to Ferguson’s lectures on the Holy Spirit here.